[cisco-ttl] Cisco Security Advisory: Cisco IOS User Datagram Protocol Delivery Issue For IPv4/IPv6 Dual-stack Routers

From: Cisco Systems Product Security Incident Response Team <psirt_at_....>
Date: Wed, 26 Mar 2008 17:00:00 +0100


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Cisco Security Advisory: Cisco IOS User Datagram Protocol Delivery

                         Issue For IPv4/IPv6 Dual-stack Routers

Advisory ID: cisco-sa-20080326-IPv4IPv6

http://www.cisco.com/warp/public/707/cisco-sa-20080326-IPv4IPv6.shtml

Revision 1.0

For Public Release 2008 March 26 1600 UTC (GMT)

Summary


A device running Cisco IOS software that has Internet Protocol version 6 (IPv6) enabled may be subject to a denial of service (DoS) attack. For the device to be affected by this vulnerability the device also has to have certain Internet Protocol version 4 (IPv4) User Datagram Protocol (UDP) services enabled. To exploit this vulnerability an offending IPv6 packet must be targeted to the device. Packets that are routed throughout the router can not trigger this vulnerability. Successful exploitation will prevent the interface from receiving any additional traffic. The only exception is Resource Reservation Protocol (RSVP) service, which if exploited, will cause the device to crash. Only the interface on which the vulnerability was exploited will be affected.

Cisco is providing fixed software to address this issue. There are workarounds available to mitigate the effects of the vulnerability.

This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20080326-IPv4IPv6.shtml

Note: The March 26, 2008 publication includes five Security Advisories. The Advisories all affect Cisco's Internetwork Operating System (IOS). Each Advisory lists the releases that correct the vulnerability described in the Advisory, and the Advisories also detail the releases that correct the vulnerabilities in all five Advisories. Please reference the following software table to find a release which fixes all published Security Advisories as of March 26th, 2008.

Individual publication links are listed below:

Affected Products


Vulnerable Products

+------------------

Only Cisco IOS software releases that have IPv6 enabled are affected by this vulnerability. In order to be vulnerable both support for IPv6 protocol and IPv4 UDP-based services must be enabled on the device. The IPv6 is not enabled by default in Cisco IOS software.

To determine the software running on a Cisco IOS product, log in to the device and issue the show version command to display the system banner. Cisco IOS software will identify itself as "Internetwork Operating System Software" or simply "IOS." On the next line of output, the image name will be displayed between parentheses, followed by "Version" and the Cisco IOS software release name. Other Cisco devices will not have the show version command, or will give different output.

The following example shows output from a device running a Cisco IOS image:

    Router>show version
    Cisco IOS Software, 1841 Software (C1841-ADVSECURITYK9-M), Version 12.4(15)T2, RELEASE SOFTWARE (fc7)     Technical Support: http://www.cisco.com/techsupport     Copyright (c) 1986-2008 by Cisco Systems, Inc.     Compiled Thu 17-Jan-08 23:12 by prod_rel_team

Additional information about Cisco IOS software release naming is available at the following link:
http://www.cisco.com/en/US/products/sw/iosswrel/ps1828/products_white_paper09186a008018305e.shtml.

In order for an interface to be vulnerable two conditions must be satisfied:

  1. An interface must have IPv6 enabled.
  2. One or more of the following IPv4 UDP-based services must be enabled: TACACS - port 49 Domain Name System (DNS) server - port 53 Resource Reservation Protocol (RSVP) - port 1698 Layer Two Forwarding (L2F)/Layer Two Tunnel Protocol (L2TP) - port 1701 IP SLA Responder - port 1967 Media Gateway Control Protocol (MGCP) - port 2427 Session Initiation Protocol (SIP) - port 5060

No other IPv4 UDP-based services are known to be affected.

How To Verify If IPv6 Is Enabled

+-------------------------------

IPv6 protocol is enabled on an interface if either or both of the following configuration lines are present in the configuration:

    Router#show running-config
    interface FastEthernet0/1
     ipv6 address 2001:0DB8:C18:1::/64 eui-64

    Router#show running-config
    interface FastEthernet0/1
     ipv6 enabled

If any of the interfaces contain either or both of the ipv6 lines then IPv6 is enabled on that particular interface.

How To Verify If IPv4 UDP-based Services Are Enabled

+---------------------------------------------------

To determine whether device is affected or not, use the show ip sockets command to display all UDP ports device is listening to. In some newer IOS releases the command show ip sockets is obsoleted, and the alternate command show udp can be used instead. The output is identical to the show ip sockets command.

The device is vulnerable if the Local Port column (fifth from the left) in the output of show ip sockets contains any of the port numbers listed in the example below.

    Router#show ip sockets

    Proto    Remote      Port      Local       Port  In Out Stat TTY OutputIF
    17 192.168.100.1      49 192.168.100.2       49   0   0   11   0 
    17 0.0.0.0             0 192.168.100.2       53   0   0  211   0 
    17   --listen--          192.168.100.2     1698   0   0    1   0 
    17 192.168.100.1    1701 192.168.100.2     1701   1   0 1021   0
    17 0.0.0.0             0 192.168.100.2     1967   0   0  211   0 
    17 0.0.0.0             0  --any--          2427   0   0  211   0
    17 0.0.0.0             0  --any--          5060   0   0  211   0

Products Confirmed Not Vulnerable

+--------------------------------

No other Cisco products are currently known to be affected by this vulnerability.

Any device running Cisco IOS without IPv6 enabled is not vulnerable. Cisco IOS XR and Cisco PIX/ASA are not affected.

Details


To exploit this vulnerability an offending IPv6 packet must be targeted to the device. Packets that are routed throughout the router can not trigger this vulnerability. Successful exploitation of the vulnerability may result in one of the following two conditions:

  1. The device will crash if RSVP service is configured on the interface.
  2. Any other affected IPv4 UDP-based service will prevent the interface from receiving additional traffic. Only the interface on which the vulnerability is exploited will be affected.

This vulnerability is independent of the interface media type. A blocked interface will immediately stop receiving any subsequent packets destined to the device itself until it is unblocked. It is possible to unblock the interface using methods other than a device reload. These methods are described in the Workarounds section. All other interfaces are unaffected and will continue receiving and transmitting packets.

Blocked interface may allow transit traffic to flow for a period of time. Transit traffic may continue to flow until either the respective routing entry or Address Resolution Protocol (ARP) entry expires, whichever event occurs first. Depending on the circumstances the transit traffic can stop flowing through the blocked interface within a few seconds or continue up to four hours (which is the ARP cache default lifetime). After that no further transit traffic will flow through the blocked interface.

No other IPv4 UDP-based services are known to be affected by this vulnerability.

This vulnerability is documented in Cisco Bug ID CSCse56501, and has been assigned the Common Vulnerabilities and Exposures (CVE) ID CVE-2008-1153. Identification Of Vulnerability Exploitation

+-------------------------------------------

The show interfaces command can be used to view the input queue size to identify a blocked input interface. A device under attack, but not yet blocked will show the Input queue size increasing without a subsequent decrease. If the current size (in this case, 76) is larger than the maximum size (75), the input queue is blocked. The value of 75 is the default value and it can be changed using the interface command hold-queue X in .

    Router#show interfaces FastEthernet 0/1 | include queue

      Input queue: 76/75/0/0 (size/max/drops/flushes); Total output drops: 0
      Output queue: 0/40 (size/max)

The example above shows that the interface FastEthernet0/1 is blocked.

The show ip sockets command can be used to determine which protocol blocks the interface. If In column (sixth from the left) of the output contains any other number than zero (0) that is an indication that packets of that particular protocol are blocking, or starting to block, the interface. The following example shows DNS packets that are beginning to fill the input queue of the interface. The interface is not completely blocked because only 13 packets are in the input queue.

    Router#show ip sockets

    Proto    Remote      Port      Local       Port  In Out Stat TTY OutputIF
    17 192.168.100.1      49 192.168.100.2       49   0   0   11   0 
    17 0.0.0.0             0 192.168.100.2       53  13   0  211   0 
    17   --listen--          192.168.100.2     1698   0   0    1   0 
    17 192.168.100.1    1701 192.168.100.2     1701   1   0 1021   0
    17 0.0.0.0             0 192.168.100.2     1967   0   0  211   0 
    17 0.0.0.0             0  --any--          2427   0   0  211   0
    17 0.0.0.0             0  --any--          5060   0   0  211   0

The output of the show ip sockets command does not provide information on interfaces. It is possible that packets from multiple protocols may be blocking a single interface. The output of the command must be interpreted with the device's configuration to establish the affected port.

Additional methods that can be used to detect blocked interfaces are described in "Cisco Applied Mitigation Bulletin: User Datagram Protocol Delivery Issue For IPv4/IPv6 Dual-Stack Routers" document available at
http://www.cisco.com/warp/public/707/cisco-amb-20080326-IPv4IPv6.shtml. The method utilizes Embedded Event Manager (EEM) and Applets or an EEM Script.

Vulnerability Scoring Details


Cisco has provided scores for the vulnerabilities in this advisory based on the Common Vulnerability Scoring System (CVSS). The CVSS scoring in this Security Advisory is done in accordance with CVSS version 2.0.

CVSS is a standards-based scoring method that conveys vulnerability severity and helps determine urgency and priority of response.

Cisco has provided a base and temporal score. Customers can then compute environmental scores to assist in determining the impact of the vulnerability in individual networks.

Cisco has provided an FAQ to answer additional questions regarding CVSS at
http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html

Cisco has also provided a CVSS calculator to help compute the environmental impact for individual networks at http://intellishield.cisco.com/security/alertmanager/cvss

CSCse56501 - UDP delivery issue when IPv4 and IPv6 are bound to the

             same socket

  CVSS Base Score - 7.8

  Access Vector            - Network
  Access Complexity        - Low
  Authentication           - None
  Confidentiality Impact   - None
  Integrity Impact         - None
  Availability Impact      - Complete

  CVSS Temporal Score - 6.4

  Exploitability           - Functional
  Remediation Level        - Official-Fix
  Report Confidence        - Confirmed

Impact


Successful exploitation of the vulnerability can result in one of the following two conditions:

  1. The device will crash if RSVP service is configured on the interface.
  2. Any other affected IPv4 UDP-based service will prevent the interface from receiving additional traffic. Only the interface on which the vulnerability is exploited will be affected.

Software Versions and Fixes


When considering software upgrades, also consult http://www.cisco.com/go/psirt and any subsequent advisories to determine exposure and a complete upgrade solution.

In all cases, customers should exercise caution to be certain the devices to be upgraded contain sufficient memory and that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, contact the Cisco Technical Assistance Center (TAC) or your contracted maintenance provider for assistance.

Each row of the Cisco IOS software table (below) names a Cisco IOS release train. If a given release train is vulnerable, then the earliest possible releases that contain the fix (along with the anticipated date of availability for each, if applicable) are listed in the "First Fixed Release" column of the table. The "Recommended Release" column indicates the releases which have fixes for all the published vulnerabilities at the time of this Advisory. A device running a release in the given train that is earlier than the release in a specific column (less than the First Fixed Release) is known to be vulnerable. Cisco recommends upgrading to a release equal to or later than the release in the "Recommended Releases" column of the table.

+----------------------------------------+
|   Major    | Availability of Repaired  |
|  Release   |         Releases          |
|------------+---------------------------|
|  Affected  | First Fixed | Recommended |
| 12.0-Based |   Release   |   Release   |
|  Releases  |             |             |
|----------------------------------------|
|    There are no affected 12.0 based    |
|                releases                |
|----------------------------------------|
|  Affected  | First Fixed | Recommended |
| 12.1-Based |   Release   |   Release   |
|  Releases  |             |             |
|------------+-------------+-------------|
| 12.1       | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1AA     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1AX     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1AY     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1AZ     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1CX     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1DA     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1DB     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1DC     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1E      | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1EA     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1EB     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1EC     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1EO     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1EU     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1EV     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1EW     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1EX     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1EY     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1EZ     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1GA     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1GB     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1T      | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XA     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XB     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XC     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XD     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XE     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XF     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XG     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XH     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XI     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XJ     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XK     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XL     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XM     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XN     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XO     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XP     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XQ     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XR     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XS     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XT     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.1XU     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.1XV     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
| 12.1XW     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XX     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XY     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1XZ     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.1YA     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.1YB     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.1YC     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.1YD     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Releases    |             |
|            | prior to    |             |
|            | 12.1(5)YE6  |             |
|            | are         |             |
|            | vulnerable, |             |
| 12.1YE     | release     | 12.3(26)    |
|            | 12.1(5)YE6  |             |
|            | and later   |             |
|            | are not     |             |
|            | vulnerable; |             |
|            | first fixed |             |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.1YF     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
| 12.1YG     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.1YH     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.1YI     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
| 12.1YJ     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|  Affected  | First Fixed | Recommended |
| 12.2-Based |   Release   |   Release   |
|  Releases  |             |             |
|------------+-------------+-------------|
| 12.2       | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2B      | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2BC     | first fixed | 12.3(23)BC1 |
|            | in 12.3BC   |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2BW     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2BY     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2BZ     | first fixed |             |
|            | in 12.3XI   |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2CX     | first fixed | 12.3(23)BC1 |
|            | in 12.3BC   |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2CY     | first fixed | 12.3(23)BC1 |
|            | in 12.3BC   |             |
|------------+-------------+-------------|
| 12.2CZ     | Vulnerable; |             |
|            | contact TAC |             |
|------------+-------------+-------------|
| 12.2DA     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2DD     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2DX     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            |             | 12.2(25)    |
|            |             | EWA13       |
|            | Vulnerable; |             |
| 12.2EU     | first fixed | 12.2(31)    |
|            | in 12.2SG   | SGA5        |
|            |             |             |
|            |             | 12.2(44)SG  |
|------------+-------------+-------------|
|            |             | 12.2(25)    |
|            |             | EWA13       |
|            | Vulnerable; |             |
| 12.2EW     | first fixed | 12.2(31)    |
|            | in 12.2SG   | SGA5        |
|            |             |             |
|            |             | 12.2(44)SG  |
|------------+-------------+-------------|
|            | 12.2(25)    |             |
|            | EWA10       | 12.2(25)    |
| 12.2EWA    |             | EWA13       |
|            | 12.2(25)    |             |
|            | EWA11       |             |
|------------+-------------+-------------|
|            | 12.2(35)EX1 |             |
| 12.2EX     |             | 12.2(40)EX1 |
|            | 12.2(37)EX  |             |
|------------+-------------+-------------|
| 12.2EY     | 12.2(37)EY  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2EZ     | first fixed |             |
|            | in 12.2SEE  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2FX     | first fixed |             |
|            | in 12.2SEE  |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.2(25)    |
| 12.2FY     | first fixed | SEG4        |
|            | in 12.2SEG  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2FZ     | first fixed | 12.2(44)SE1 |
|            | in 12.2SE   |             |
|------------+-------------+-------------|
| 12.2IXA    | Vulnerable; |             |
|            | contact TAC |             |
|------------+-------------+-------------|
| 12.2IXB    | Vulnerable; |             |
|            | contact TAC |             |
|------------+-------------+-------------|
| 12.2IXC    | Vulnerable; |             |
|            | contact TAC |             |
|------------+-------------+-------------|
| 12.2IXD    | Vulnerable; |             |
|            | contact TAC |             |
|------------+-------------+-------------|
| 12.2IXE    | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2JA     | first fixed |             |
|            | in 12.3JA   |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2JK     | first fixed | 12.4(15)T4  |
|            | in 12.4T    |             |
|------------+-------------+-------------|
| 12.2MB     | Vulnerable; |             |
|            | contact TAC |             |
|------------+-------------+-------------|
| 12.2MC     | 12.2(15)    | 12.4(18a)   |
|            | MC2h        |             |
|------------+-------------+-------------|
|            | 12.2(14)S18 |             |
|            |             |             |
|            | 12.2(18)S13 |             |
| 12.2S      |             | 12.2(25)S15 |
|            | 12.2(20)S14 |             |
|            |             |             |
|            | 12.2(25)S13 |             |
|------------+-------------+-------------|
|            | 12.2(28)SB7 |             |
|            |             |             |
|            | 12.2(31)SB5 |             |
| 12.2SB     |             | 12.2(28)    |
|            | 12.2(33)SB; | SB12        |
|            | Available   |             |
|            | on          |             |
|            | 31-MAR-2008 |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
|            | first fixed |             |
| 12.2SBC    | in 12.2SB;  | 12.2(28)    |
|            | Available   | SB12        |
|            | on          |             |
|            | 31-MAR-2008 |             |
|------------+-------------+-------------|
| 12.2SCA    | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|            | 12.2(35)SE4 |             |
| 12.2SE     |             | 12.2(44)SE1 |
|            | 12.2(37)SE  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2SEA    | first fixed |             |
|            | in 12.2SEE  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2SEB    | first fixed |             |
|            | in 12.2SEE  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2SEC    | first fixed |             |
|            | in 12.2SEE  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2SED    | first fixed |             |
|            | in 12.2SEE  |             |
|------------+-------------+-------------|
| 12.2SEE    | 12.2(25)    |             |
|            | SEE4        |             |
|------------+-------------+-------------|
| 12.2SEF    | 12.2(25)    | 12.2(44)SE1 |
|            | SEF3        |             |
|------------+-------------+-------------|
| 12.2SEG    | 12.2(25)    | 12.2(25)    |
|            | SEG3        | SEG4        |
|------------+-------------+-------------|
|            | 12.2(25)SG3 |             |
|            |             |             |
| 12.2SG     | 12.2(31)SG3 | 12.2(44)SG  |
|            |             |             |
|            | 12.2(37)SG  |             |
|------------+-------------+-------------|
|            | 12.2(31)    |             |
|            | SGA2        |             |
|            |             |             |
|            | 12.2(31)    |             |
|            | SGA3        | 12.2(31)    |
| 12.2SGA    |             | SGA5        |
|            | 12.2(31)    |             |
|            | SGA6;       |             |
|            | Available   |             |
|            | on          |             |
|            | 07-APR-2008 |             |
|------------+-------------+-------------|
| 12.2SL     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.2SM     | Vulnerable; |             |
|            | contact TAC |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2SO     | migrate to  | 12.2(29)SVD |
|            | any release |             |
|            | in 12.2SVA  |             |
|------------+-------------+-------------|
| 12.2SRA    | 12.2(33)    | 12.2(33)    |
|            | SRA4        | SRA7        |
|------------+-------------+-------------|
|            |             | 12.2(33)    |
|            | 12.2(33)    | SRB3;       |
| 12.2SRB    | SRB1        | Available   |
|            |             | on          |
|            |             | 31-MAR-2008 |
|------------+-------------+-------------|
| 12.2SRC    | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2SU     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
| 12.2SV     | 12.2(29b)SV | 12.2(29b)SV |
|------------+-------------+-------------|
| 12.2SVA    | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.2SVC    | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.2SVD    | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.2SW     | Vulnerable; |             |
|            | contact TAC |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.2(18)    |
| 12.2SX     | first fixed | SXF13       |
|            | in 12.2SXF  |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.2(18)    |
| 12.2SXA    | first fixed | SXF13       |
|            | in 12.2SXF  |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.2(18)    |
| 12.2SXB    | first fixed | SXF13       |
|            | in 12.2SXF  |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.2(18)    |
| 12.2SXD    | first fixed | SXF13       |
|            | in 12.2SXF  |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.2(18)    |
| 12.2SXE    | first fixed | SXF13       |
|            | in 12.2SXF  |             |
|------------+-------------+-------------|
|            | 12.2(18)    |             |
|            | SXF10a      |             |
|            |             |             |
|            | 12.2(18)    |             |
|            | SXF12a      | 12.2(18)    |
| 12.2SXF    |             | SXF13       |
|            | 12.2(18)    |             |
|            | SXF13a      |             |
|            |             |             |
|            | 12.2(18)    |             |
|            | SXF9        |             |
|------------+-------------+-------------|
| 12.2SXH    | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.2(18)    |
| 12.2SY     | first fixed | SXF13       |
|            | in 12.2SXF  |             |
|------------+-------------+-------------|
|            |             | 12.2(25)S15 |
|            | Vulnerable; |             |
| 12.2SZ     | first fixed | 12.2(28)    |
|            | in 12.2S    | SB12        |
|            |             |             |
|            |             | 12.2(33)SRC |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2T      | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
| 12.2TPC    | 12.2(8)     |             |
|            | TPC10b      |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
|            | first fixed |             |
| 12.2UZ     | in 12.2SB;  | 12.2(28)    |
|            | Available   | SB12        |
|            | on          |             |
|            | 31-MAR-2008 |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XA     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XB     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XC     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XD     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XE     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XF     | first fixed | 12.3(23)BC1 |
|            | in 12.3BC   |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XG     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XH     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XI     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XJ     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XK     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XL     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XM     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
| 12.2XN     | 12.2(33)XN1 | 12.3(26)    |
|------------+-------------+-------------|
| 12.2XO     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XQ     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XR     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
| 12.2XS     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XT     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XU     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XV     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2XW     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | 12.2(4)     |             |
|            | YA13;       |             |
| 12.2YA     | Available   | 12.3(26)    |
|            | on          |             |
|            | 31-MAR-2008 |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YB     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YC     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YD     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            |             | 12.2(25)S15 |
|            | Vulnerable; |             |
| 12.2YE     | first fixed | 12.2(28)    |
|            | in 12.2S    | SB12        |
|            |             |             |
|            |             | 12.2(33)SRC |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YF     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YG     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YH     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YJ     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YK     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YL     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YM     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YN     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.2(18)    |
| 12.2YO     | first fixed | SXF13       |
|            | in 12.2SXF  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YP     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YQ     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YR     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
| 12.2YS     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YT     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YU     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YV     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YW     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YX     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2YY     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            |             | 12.2(25)S15 |
|            | Vulnerable; |             |
| 12.2YZ     | first fixed | 12.2(28)    |
|            | in 12.2S    | SB12        |
|            |             |             |
|            |             | 12.2(33)SRC |
|------------+-------------+-------------|
|            | Vulnerable; | 12.2(18)    |
| 12.2ZA     | first fixed | SXF13       |
|            | in 12.2SXF  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2ZB     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2ZC     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
| 12.2ZD     | Vulnerable; |             |
|            | contact TAC |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2ZE     | first fixed | 12.3(26)    |
|            | in 12.3     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2ZF     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.4(15)T4  |
| 12.2ZG     | first fixed |             |
|            | in 12.3YG   | 12.4(18a)   |
|------------+-------------+-------------|
| 12.2ZH     | 12.2(13)ZH9 | 12.2(13)    |
|            |             | ZH11        |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2ZJ     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.4(15)T4  |
| 12.2ZL     | first fixed |             |
|            | in 12.4     | 12.4(18a)   |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2ZP     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.2ZU     | migrate to  | 12.2(33)    |
|            | any release | SXH2        |
|            | in 12.2SXH  |             |
|------------+-------------+-------------|
| 12.2ZY     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|  Affected  | First Fixed | Recommended |
| 12.3-Based |   Release   |   Release   |
|  Releases  |             |             |
|------------+-------------+-------------|
|            | 12.3(17c)   |             |
|            |             |             |
|            | 12.3(18a)   |             |
| 12.3       |             | 12.3(26)    |
|            | 12.3(19a)   |             |
|            |             |             |
|            | 12.3(23)    |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3B      | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | 12.3(17b)   |             |
|            | BC8         |             |
|            |             |             |
| 12.3BC     | 12.3(21a)   | 12.3(23)BC1 |
|            | BC2         |             |
|            |             |             |
|            | 12.3(23)BC  |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3BW     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
| 12.3EU     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|            | 12.3(11)JA4 |             |
| 12.3JA     |             |             |
|            | 12.3(7)JA5  |             |
|------------+-------------+-------------|
| 12.3JEA    | 12.3(8)JEA2 | 12.3(8)JEA4 |
|------------+-------------+-------------|
| 12.3JEB    | 12.3(8)JEB1 | 12.3(8)JEB2 |
|------------+-------------+-------------|
| 12.3JEC    | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
|            | 12.3(2)JK3  |             |
| 12.3JK     |             | 12.3(8)JK1  |
|            | 12.3(8)JK   |             |
|------------+-------------+-------------|
| 12.3JL     | 12.3(2)JL2  | 12.3(2)JL4  |
|------------+-------------+-------------|
| 12.3JX     | 12.3(7)JX9  | 12.3(7)JX10 |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3T      | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
| 12.3TPC    | 12.3(4)     |             |
|            | TPC11b      |             |
|------------+-------------+-------------|
| 12.3VA     | Vulnerable; |             |
|            | contact TAC |             |
|------------+-------------+-------------|
|            |             | 12.3(2)XA7; |
| 12.3XA     | 12.3(2)XA6  | Available   |
|            |             | on          |
|            |             | 31-MAR-2008 |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3XB     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            |             | 12.4(15)T4  |
| 12.3XC     | 12.3(2)XC5  |             |
|            |             | 12.4(18a)   |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3XD     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | 12.3(2)XE6; | 12.4(15)T4  |
| 12.3XE     | Available   |             |
|            | on          | 12.4(18a)   |
|            | 31-MAR-2008 |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3XF     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.4(15)T4  |
| 12.3XG     | first fixed |             |
|            | in 12.3YG   | 12.4(18a)   |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3XH     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
| 12.3XI     | 12.3(7)XI10 |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.3(14)    |
| 12.3XJ     | first fixed | YX11        |
|            | in 12.3YX   |             |
|            |             | 12.4(15)T4  |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3XK     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3XQ     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            |             | 12.3(7)XR8; |
| 12.3XR     | 12.3(7)XR7  | Available   |
|            |             | on          |
|            |             | 31-MAR-2008 |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3XS     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3XU     | first fixed | 12.4(15)T4  |
|            | in 12.4T    |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.3(14)    |
| 12.3XW     | first fixed | YX11        |
|            | in 12.3YX   |             |
|            |             | 12.4(15)T4  |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3XY     | first fixed | 12.4(18a)   |
|            | in 12.4     |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.4(15)T4  |
| 12.3YA     | first fixed |             |
|            | in 12.4     | 12.4(18a)   |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3YD     | first fixed | 12.4(15)T4  |
|            | in 12.4T    |             |
|------------+-------------+-------------|
|            | Vulnerable; | 12.3(14)    |
| 12.3YF     | first fixed | YX11        |
|            | in 12.3YX   |             |
|            |             | 12.4(15)T4  |
|------------+-------------+-------------|
| 12.3YG     | 12.3(8)YG6  | 12.4(15)T4  |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3YH     | first fixed | 12.4(15)T4  |
|            | in 12.4T    |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3YI     | first fixed | 12.4(15)T4  |
|            | in 12.4T    |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3YJ     | first fixed | 12.4(15)T4  |
|            | in 12.4T    |             |
|------------+-------------+-------------|
| 12.3YK     | 12.3(11)YK3 | 12.4(15)T4  |
|------------+-------------+-------------|
| 12.3YM     | 12.3(14)    | 12.3(14)    |
|            | YM10        | YM12        |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3YQ     | first fixed | 12.4(15)T4  |
|            | in 12.4T    |             |
|------------+-------------+-------------|
|            | 12.3(11)    |             |
|            | YS3;        |             |
| 12.3YS     | Available   | 12.4(15)T4  |
|            | on          |             |
|            | 31-MAR-2008 |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3YT     | first fixed | 12.4(15)T4  |
|            | in 12.4T    |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.3YU     | first fixed |             |
|            | in 12.4XB   |             |
|------------+-------------+-------------|
| 12.3YX     | 12.3(14)YX8 | 12.3(14)    |
|            |             | YX11        |
|------------+-------------+-------------|
| 12.3YZ     | 12.3(11)YZ2 |             |
|------------+-------------+-------------|
|  Affected  | First Fixed | Recommended |
| 12.4-Based |   Release   |   Release   |
|  Releases  |             |             |
|------------+-------------+-------------|
|            | 12.4(10c)   |             |
|            |             |             |
|            | 12.4(12)    |             |
|            |             |             |
|            | 12.4(17a)   |             |
|            |             |             |
| 12.4       | 12.4(3h)    | 12.4(18a)   |
|            |             |             |
|            | 12.4(5c)    |             |
|            |             |             |
|            | 12.4(7e)    |             |
|            |             |             |
|            | 12.4(8d)    |             |
|------------+-------------+-------------|
| 12.4JA     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.4JK     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.4JMA    | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.4JMB    | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.4JMC    | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.4JX     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.4MD     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.4MR     | 12.4(12)MR  | 12.4(16)MR2 |
|------------+-------------+-------------|
| 12.4SW     | 12.4(11)SW3 | 12.4(15)SW  |
|------------+-------------+-------------|
|            | 12.4(11)T2  |             |
|            |             |             |
|            | 12.4(15)T   |             |
|            |             |             |
|            | 12.4(2)T6   |             |
| 12.4T      |             | 12.4(15)T4  |
|            | 12.4(4)T8   |             |
|            |             |             |
|            | 12.4(6)T8   |             |
|            |             |             |
|            | 12.4(9)T3   |             |
|------------+-------------+-------------|
|            | Vulnerable; |             |
| 12.4XA     | first fixed | 12.4(15)T4  |
|            | in 12.4T    |             |
|------------+-------------+-------------|
| 12.4XB     | 12.4(2)XB6  |             |
|------------+-------------+-------------|
| 12.4XC     | 12.4(4)XC7  |             |
|------------+-------------+-------------|
| 12.4XD     | 12.4(4)XD7  | 12.4(4)XD10 |
|------------+-------------+-------------|
| 12.4XE     | 12.4(6)XE2  | 12.4(15)T4  |
|------------+-------------+-------------|
| 12.4XF     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.4XG     | 12.4(9)XG2  | 12.4(9)XG2  |
|------------+-------------+-------------|
| 12.4XJ     | 12.4(11)XJ4 | 12.4(15)T4  |
|------------+-------------+-------------|
| 12.4XK     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.4XL     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.4XM     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.4XN     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.4XT     | 12.4(6)XT1  | 12.4(6)XT2  |
|------------+-------------+-------------|
| 12.4XV     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.4XW     | Not         |             |
|            | Vulnerable  |             |
|------------+-------------+-------------|
| 12.4XY     | Not         |             |
|            | Vulnerable  |             |
+----------------------------------------+

Workarounds


A blocked interface can be unblocked by disabling the UDP service whose packets are blocking the interface. This procedure can restore normal operation of the interface without rebooting the device. The procedure for disabling vulnerable services are described in the "If IPv4 UDP-based Services Are Not Required" section.

The following workarounds are options that may be available depending on the Cisco IOS software running on the device and the operating environment. The workarounds depend on whether IPv6 or any of the affected UDP services are required for the normal operation.

If IPv6 Protocol Is Not Required

+-------------------------------

Disable IPv6. To disable IPv6 use the following commands:

    Router(config)#interface FastEthernet0/0     Router(config-if)#no ipv6 address

or

    Router(config)#interface FastEthernet0/0     Router(config-if)#no ipv6 enable

If RSVP is the only affected service that is configured it is sufficient to disable IPv6 only on the interface where RSVP is configured. If any other affected UDP service is present on the device then IPv6 would have to be disabled from all interfaces.

If IPv4 UDP-based Services Are Not Required

+------------------------------------------

Disable all affected IPv4 UDP-based services.

Disabling TACACS
+---------------

To disable TACACS use the following commands:

    Router(config)#no tacacs-server host <IP-address>

or

    Router(config)#no tacacs-server administration

Disabling DNS
+------------

To disable DNS use the following command:

    Router(config)#no ip dns server

Disabling RSVP
+-------------

To disable RSVP use the following commands:

    Router(config)#interface <Interface>     Router(config)#no ip rsvp bandwidth

Disabling L2F/L2TP

+-----------------

To disable L2F/L2TP use the following commands:

    Router(config)#clear vpdn tunnel l2tp all
    Router(config)#no vpdn-group <group-name>
    Router(config)#no vpdn enable

Disabling IP SLA Responder

+-------------------------

To disable IP SLA Responder use the following command:

    Router(config)#no ip sla monitor responder

Disabling MGCP
+-------------

To disable MGCP use the following command:

    Router(config)#no mgcp

Disabling SIP
+------------

To disable SIP use the following commands:

    Router(config)#sip-ua
    Router(config-sip-ua)#no transport udp
    Router(config-sip-ua)#no transport tcp

If IPv4 UDP-based Services Are Required

+---------------------------------------

By deploying IPv6 Access Control List (ACL) it is possible to prevent offending IPv6 packets reaching vulnerable UDP services. The ACL in the following example will block all IPv6 traffic from reaching vulnerable services.

    Router(config)#ipv6 access-list protect_IPv4_services
    Router(config-ipv6-acl)#deny udp any 2001:DB8:1:128::/64 eq tacacs
    Router(config-ipv6-acl)#deny udp any 2001:DB8:1:128::/64 eq domain
    Router(config-ipv6-acl)#deny udp any 2001:DB8:1:128::/64 eq 1698
    Router(config-ipv6-acl)#deny udp any 2001:DB8:1:128::/64 eq 1701
    Router(config-ipv6-acl)#deny udp any 2001:DB8:1:128::/64 eq 1967
    Router(config-ipv6-acl)#deny udp any 2001:DB8:1:128::/64 eq 2427
    Router(config-ipv6-acl)#deny udp any 2001:DB8:1:128::/64 eq 5060
    
    !-- Permit/deny all other Layer 3 and Layer 4 traffic in accordance        
    !-- with existing security policies and configurations                     
    !
    !-- Allow all other IPv6 traffic     

    Router(config-ipv6-acl)#permit ipv6 any 2001:db8:1:128::/64     

    !
    !     

    Router(config)#interface FastEthernet0/1     Router(config-if)#ipv6 traffic-filter protect_IPv4_services in

Additional mitigation techniques that can be deployed on Cisco devices within the network are available in the Cisco Applied Mitigation Bulletin companion document for this advisory:

http://www.cisco.com/warp/public/707/cisco-amb-20080326-IPv4IPv6.shtml

Obtaining Fixed Software


Cisco has released free software updates that address this vulnerability. Prior to deploying software, customers should consult their maintenance provider or check the software for feature set compatibility and known issues specific to their environment.

Customers may only install and expect support for the feature sets they have purchased. By installing, downloading, accessing or otherwise using such software upgrades, customers agree to be bound by the terms of Cisco's software license terms found at http://www.cisco.com/en/US/products/prod_warranties_item09186a008088e31f.html or as otherwise set forth at Cisco.com Downloads at http://www.cisco.com/public/sw-center/sw-usingswc.shtml.

Do not contact psirt_at_cisco.com or security-alert_at_cisco.com for software upgrades.

Customers with Service Contracts

+-------------------------------

Customers with contracts should obtain upgraded software through their regular update channels. For most customers, this means that upgrades should be obtained through the Software Center on Cisco's worldwide website at http://www.cisco.com.

Customers using Third Party Support Organizations

+------------------------------------------------

Customers whose Cisco products are provided or maintained through prior or existing agreements with third-party support organizations, such as Cisco Partners, authorized resellers, or service providers should contact that support organization for guidance and assistance with the appropriate course of action in regards to this advisory.

The effectiveness of any workaround or fix is dependent on specific customer situations, such as product mix, network topology, traffic behavior, and organizational mission. Due to the variety of affected products and releases, customers should consult with their service provider or support organization to ensure any applied workaround or fix is the most appropriate for use in the intended network before it is deployed.

Customers without Service Contracts

+----------------------------------

Customers who purchase direct from Cisco but do not hold a Cisco service contract, and customers who purchase through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should acquire upgrades by contacting the Cisco Technical Assistance Center (TAC). TAC contacts are as follows.

Customers should have their product serial number available and be prepared to give the URL of this notice as evidence of entitlement to a free upgrade. Free upgrades for non-contract customers must be requested through the TAC.

Refer to http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml for additional TAC contact information, including localized telephone numbers, and instructions and e-mail addresses for use in various languages.

Exploitation and Public Announcements


The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability described in this advisory.

This vulnerability was encountered in customer networks.

Status of this Notice: FINAL


THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME. A stand-alone copy or Paraphrase of the text of this document that omits the distribution URL in the following section is an uncontrolled copy, and may lack important information or contain factual errors.

Distribution


This advisory is posted on Cisco's worldwide website at:

http://www.cisco.com/warp/public/707/cisco-sa-20080326-IPv4IPv6.shtml

In addition to worldwide web posting, a text version of this notice is clear-signed with the Cisco PSIRT PGP key and is posted to the following e-mail and Usenet news recipients.

Future updates of this advisory, if any, will be placed on Cisco's worldwide website, but may or may not be actively announced on mailing lists or newsgroups. Users concerned about this problem are encouraged to check the above URL for any updates.

Revision History


+---------------------------------------+
| Revision |             | Initial      |
| 1.0      | 2008-Mar-26 | public       |
|          |             | release      |
+---------------------------------------+

Cisco Security Procedures


Complete information on reporting security vulnerabilities in Cisco products, obtaining assistance with security incidents, and registering to receive security information from Cisco, is available on Cisco's worldwide website at
http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html. This includes instructions for press inquiries regarding Cisco security notices. All Cisco security advisories are available at http://www.cisco.com/go/psirt.
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