Cisco Security Advisory: IOS Heap-based Overflow Vulnerability in System Timers

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Cisco Security Advisory: ======================== IOS Heap-based Overflow Vulnerability in System Timers ====================================================== Document ID: 68064 Revision 1.0 For Public Release 2005 November 2 1600 UTC (GMT) - ----------------------------------------------------------------------- Contents ======== Summary Affected Products Background Information Regarding Heap Overflows Details Impact Software Versions and Fixes Obtaining Fixed Software Workarounds Exploitation and Public Announcements Status of This Notice: FINAL Distribution Revision History Cisco Security Procedures - ----------------------------------------------------------------------- Summary ======= The Cisco Internetwork Operating System (IOS) may permit arbitrary code execution after exploitation of a heap-based buffer overflow vulnerability. Cisco has included additional integrity checks in its software, as further described below, that are intended to reduce the likelihood of arbitrary code execution. Cisco has made free software available that includes the additional integrity checks for affected customers. This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20051102-timers.shtml. Cisco is not aware of any active exploitation of this vulnerability. This advisory documents changes to Cisco IOS? as a result of continued research related to the demonstration of the exploit for another vulnerability which occurred in July 2005 at the Black Hat USA Conference. Cisco addressed the IPv6 attack vector used in that demonstration in a separate advisory published on July 29, 2005. Affected Products ================= This security advisory applies to all Cisco products that run Cisco IOS Software. Any version of Cisco IOS prior to the versions listed in the Fixed Software table below may be susceptible to heap overflow exploitation. Cisco IOS XR is not affected. To determine the software running on a Cisco 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 IOS release name. Other Cisco devices will not have the "show version" command or will give different output. The following example identifies a Cisco product running IOS release 12.3(6) with an installed image name of C3640-I-M: Cisco Internetwork Operating System Software IOS (tm) 3600 Software (C3640-I-M), Version 12.3(6), RELEASE SOFTWARE (fc3) The next example shows a product running IOS release 12.3(11)T3 with an image name of C3845-ADVIPSERVICESK9-M: Cisco IOS Software, 3800 Software (C3845-ADVIPSERVICESK9-M), Version 12.3(11)T3, RELEASE SOFTWARE (fc4) Technical Support: http://www.cisco.com/techsupport Copyright (c) 1986-2005 by Cisco Systems, Inc. Additional information about Cisco IOS release naming can be found at http://www.cisco.com/warp/public/620/1.html. No other Cisco products are currently known to be affected by the vulnerability addressed in this advisory. Background Information Regarding Heap Overflows =============================================== As this security advisory pertains to heap overflows, the following additional information is provided to aid in understanding the terminology used in this advisory. RFC 2828 defines a vulnerability as "A flaw or weakness in a system's design, implementation, or operation and management that could be exploited to violate the system's security policy." The threat from any particular vulnerability in a system or a protocol depends on the ease and likelihood in which the normal operations of a system can be disrupted or compromised. In order to minimize the threat, each possible attack vector for a particular vulnerability should either be mitigated with protections which may prevent the circumstances required for exploitation or remediated with software that no longer contains the vulnerability. Many forms of malicious software, commonly known as "exploits", contain a payload that seeks to disrupt or compromise a system delivered through well-known attack vectors for particular vulnerabilities. In cases where it is likely that unpatched vulnerable systems exist, counter-measures are often employed to attempt to block any and all attack vectors to minimize the threat of successful exploitation. One popular attack method often found in the payload of exploits is known as a buffer overflow. A heap-based overflow is a type of buffer overflow against a data structure residing within the memory heap. The memory heap is a section of system memory used by the operating system of the device to satisfy the dynamic data storage requirements for currently running processes. In a successful heap-based overflow, the operating system fails to enforce bounds checking on a buffer, thus allowing for the possibility of overwriting adjacent locations in system memory. The threat from buffer overflows, like the one described in this advisory, may be remediated in multiple ways. One way is to remove the particular attack vector so that it no longer exists. Another way is to employ protections in the underlying system to minimize the consequences of any future buffer overflow vulnerabilities that may be discovered. Details ======= Cisco IOS may be susceptible to remote code execution through attack vectors such as specific heap-based overflows in which internal operating system timers may execute arbitrary code from portions of memory that have been overwritten via exploitation. In many cases, a heap-based overflow in Cisco IOS will simply corrupt system memory and trigger a system reload when detected by the "Check Heaps" process, which constantly monitors for such memory corruption. In a successful attack against an appropriate heap-based overflow, it is possible to achieve code execution without the device crashing immediately. Cisco has devised counter-measures by implementing extra checks to enforce the proper integrity of system timers. This extra validation should reduce the possibility of heap-based overflow attack vectors achieving remote code execution. These improvements have been documented in Cisco Bug ID CSCei61732. Impact ====== Successful exploitations of heap-based buffer overflow vulnerabilities in Cisco IOS software often result in a Denial of Service because the exploit causes the router to crash and reload due to inconsistencies in running memory. In some cases it is possible to overwrite areas of system memory and execute arbitrary code from those locations. In the event of successful remote code execution, device integrity will have been completely compromised. Software Versions and Fixes =========================== When considering software upgrades, please also consult http://www.cisco.com/en/US/products/products_security_advisories_listing.htm... 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") for assistance. Each row of the Cisco IOS software table (below) describes a release train and the platforms or products for which it is intended. If a given release train is vulnerable, then the earliest possible releases that contain the fix (the "First Fixed Release") and the anticipated date of availability for each are listed in the "Rebuild" and "Maintenance" columns. 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. The release should be upgraded at least to the indicated release or a later version (greater than or equal to the First Fixed Release label). For further information on the terms "Rebuild" and "Maintenance," please consult the following URL: http://www.cisco.com/warp/public/620/1.html. +------------------------------------------------------+ | Major | Availability of Repaired Releases | | Release | | |------------+-----------------------------------------| | Affected | | | | 12.0-Based | Rebuild | Maintenance | | Release | | | |------------+--------------------+--------------------| | 12.0 | 12.0(28d) | | |------------+-----------------------------------------| | 12.0DA | Vulnerable; migrate to 12.2(12)DA9 or | | | later | |------------+-----------------------------------------| | 12.0DB | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.0DC | Vulnerable; migrate to 12.2(15)BC2i or | | | later | |------------+-----------------------------------------| | | 12.0(28)S5 | | | |--------------------+--------------------| | 12.0S | 12.0(30)S4 | | | |--------------------+--------------------| | | 12.0(31)S1 | | |------------+-----------------------------------------| | 12.0SC | Vulnerable; migrate to 12.2(15)BC2i or | | | later | |------------+-----------------------------------------| | 12.0SL | Vulnerable; migrate to 12.0(31)S1 or | | | later | |------------+-----------------------------------------| | 12.0SP | Vulnerable; migrate to 12.0(31)S1 or | | | later | |------------+-----------------------------------------| | 12.0ST | Vulnerable; migrate to 12.0(31)S1 or | | | later | |------------+-----------------------------------------| | 12.0SX | Vulnerable; contact TAC | |------------+-----------------------------------------| | 12.0SZ | Vulnerable; migrate to 12.0(31)S1 or | | | later | |------------+-----------------------------------------| | 12.0T | Vulnerable; migrate to 12.1(27b) or | | | later | |------------+-----------------------------------------| | | 12.0(25)W5-27d | | | |--------------------+--------------------| | 12.0W5 | 12.0(28)W5-30b | | | |--------------------+--------------------| | | 12.0(28)W5-32a | | |------------+--------------------+--------------------| | 12.0WC | 12.0(5)WC13 | | |------------+-----------------------------------------| | 12.0XA | Vulnerable; migrate to 12.1(27b) or | | | later | |------------+-----------------------------------------| | 12.0XB | Vulnerable; migrate to 12.1(27b) or | | | later | |------------+-----------------------------------------| | 12.0XC | Vulnerable; migrate to 12.1(27b) or | | | later | |------------+-----------------------------------------| | 12.0XD | Vulnerable; migrate to 12.1(27b) or | | | later | |------------+-----------------------------------------| | 12.0XE | Vulnerable; migrate to 12.1(26)E3 or | | | later | |------------+-----------------------------------------| | 12.0XF | Vulnerable; migrate to 12.1(27b) or | | | later | |------------+-----------------------------------------| | 12.0XG | Vulnerable; migrate to 12.1(27b) or | | | later | |------------+-----------------------------------------| | 12.0XH | Vulnerable; migrate to 12.1(27b) or | | | later | |------------+-----------------------------------------| | 12.0XI | Vulnerable; migrate to 12.1(27b) or | | | later | |------------+-----------------------------------------| | 12.0XJ | Vulnerable; migrate to 12.1(27b) or | | | later | |------------+-----------------------------------------| | 12.0XK | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.0XL | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.0XM | Vulnerable; migrate to 12.1(27b) or | | | later | |------------+-----------------------------------------| | 12.0XN | Vulnerable; migrate to 12.1(27b) or | | | later | |------------+-----------------------------------------| | 12.0XQ | Vulnerable; migrate to 12.1(27b) or | | | later | |------------+-----------------------------------------| | 12.0XR | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.0XS | Vulnerable; migrate to 12.1(26)E3 or | | | later | |------------+-----------------------------------------| | 12.0XV | Vulnerable; migrate to 12.1(27b) or | | | later | |------------+-----------------------------------------| | Affected | | | | 12.1-Based | Rebuild | Maintenance | | Release | | | |------------+--------------------+--------------------| | 12.1 | 12.1(27b) | | |------------+-----------------------------------------| | 12.1AA | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | | Vulnerable; for c3750-ME, migrate to | | 12.1AX | 12.2(25)EY3 or later. For c2970 and | | | 3750, migrate to 12.2(25)SEB4, 12.2(25) | | | SEC2, 12.2(25)SED or later. | |------------+-----------------------------------------| | 12.1AY | Vulnerable; migrate to 12.1(22)EA4a, | | | 12.1(22)EA5a, 12.2(22)EA6 or later | |------------+-----------------------------------------| | 12.1AZ | Vulnerable; migrate to 12.1(22)EA4a, | | | 12.1(22)EA5a, 12.2(22)EA6 or later | |------------+-----------------------------------------| | 12.1CX | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.1DA | Vulnerable; migrate to 12.2(12)DA9 or | | | later | |------------+-----------------------------------------| | 12.1DB | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.1DC | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | | 12.1(8b)E20 | | | |--------------------+--------------------| | | 12.1(13)E17 | | | 12.1E |--------------------+--------------------| | | 12.1(23)E4 | | | |--------------------+--------------------| | | 12.1(26)E3 | | |------------+--------------------+--------------------| | | 12.1(22)EA4a | 12.1(22)EA6 | | 12.1EA |--------------------+--------------------| | | 12.1(22)EA5a | | |------------+--------------------+--------------------| | 12.1EB | 12.1(26)EB1 | | |------------+-----------------------------------------| | 12.1EC | Vulnerable; migrate to 12.2(15)BC2i or | | | later | |------------+-----------------------------------------| | 12.1EO | 12.1(20)EO3, | | | | available 11/30/05 | | |------------+-----------------------------------------| | 12.1EU | Vulnerable; migrate to 12.2(20)EU2 or | | | later | |------------+-----------------------------------------| | 12.1EV | Vulnerable; migrate to 12.2(26)SV1 or | | | later | |------------+-----------------------------------------| | | 12.1(12c)EW4 | | | |--------------------+--------------------| | | 12.1(13)EW4 | | | 12.1EW |--------------------+--------------------| | | 12.1(19)EW3 | | | |--------------------+--------------------| | | 12.1(20)EW4 | | |------------+-----------------------------------------| | 12.1EX | Vulnerable; migrate to 12.1(26)E3 or | | | later | |------------+-----------------------------------------| | 12.1EY | Vulnerable; migrate to 12.1(26)E3 or | | | later | |------------+-----------------------------------------| | 12.1EZ | Vulnerable; migrate to 12.1(26)E3 or | | | later | |------------+-----------------------------------------| | 12.1T | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.1XA | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.1XB | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.1XC | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.1XD | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.1XE | Vulnerable; migrate to 12.1(26)E3 or | | | later | |------------+-----------------------------------------| | 12.1XF | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1XG | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1XH | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.1XI | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.1XJ | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1XL | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1XM | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1XP | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1XQ | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1XR | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1XS | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.1XT | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1XU | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1XV | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1XW | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.1XX | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.1XY | Vulnerable; migrate to 12.2(31) or | | | later | |------------+-----------------------------------------| | 12.1YA | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1YB | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1YC | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1YD | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1YE | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1YF | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1YH | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1YI | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.1YJ | Vulnerable; migrate to 12.1(22)EA4a, | | | 12.1(22)EA5a, 12.1(22)EA6 or later | |------------+-----------------------------------------| | Affected | | | | 12.2-Based | Rebuild | Maintenance | | Release | | | |------------+--------------------+--------------------| | | 12.2(12m) | | | |--------------------+--------------------| | | 12.2(17f) | | | |--------------------+--------------------| | | 12.2(23f) | | | |--------------------+--------------------| | 12.2 | 12.2(26b) | | | |--------------------+--------------------| | | 12.2(27b) | | | |--------------------+--------------------| | | 12.2(28c) | | | |--------------------+--------------------| | | 12.2(29a) | 12.2(31) | |------------+-----------------------------------------| | 12.2B | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2BC | 12.2(15)BC2i | | |------------+-----------------------------------------| | 12.2BX | Vulnerable; migrate to 12.3(7)XI7, | | | available 15-Nov-2005 | |------------+-----------------------------------------| | 12.2BY | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2BZ | Vulnerable; migrate to 12.3(7)XI7, | | | available 15-Nov-2005 | |------------+-----------------------------------------| | 12.2CX | Vulnerable; migrate to 12.2(15)BC2i or | | | later | |------------+-----------------------------------------| | 12.2CY | Vulnerable; migrate to 12.2(15)BC2i or | | | later | |------------+-----------------------------------------| | | 12.2(15)CZ3, | | | 12.2CZ | available | | | | 3-Nov-2005 | | |------------+--------------------+--------------------| | | 12.2(10)DA4 | | | 12.2DA |--------------------+--------------------| | | 12.2(12)DA9 | | |------------+-----------------------------------------| | 12.2DD | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2DX | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2EU | 12.2(20)EU2 | | |------------+--------------------+--------------------| | | 12.2(18)EW5 | | | 12.2EW |--------------------+--------------------| | | 12.2(20)EW3 | | |------------+--------------------+--------------------| | | 12.2(20)EWA3 | | | |--------------------+--------------------| | 12.2EWA | 12.2(25)EWA3 | | | |--------------------+--------------------| | | 12.2(25)EWA4 | | |------------+--------------------+--------------------| | | | 12.2(25)EX, | | 12.2EX | | available | | | | 03-Nov-2005 | |------------+--------------------+--------------------| | 12.2EY | 12.2(25)EY3 | Migrate to 12.2 | | | | (25)SED | |------------+-----------------------------------------| | 12.2EZ | Vulnerable; migrate to 12.2(25)SEC2, | | | 12.2(25)SED or later | |------------+-----------------------------------------| | | | 12.2(25)FX, | | 12.2FX | | available | | | | 07-Nov-2005 | |------------+--------------------+--------------------| | 12.2FY | | 12.2(25)FY | |------------+-----------------------------------------| | 12.2JA | Vulnerable; migrate to 12.3(7)JA1 or | | | later | |------------+-----------------------------------------| | 12.2JK | 12.2(15)JK5 | | |------------+--------------------+--------------------| | 12.2MB | 12.2(4)MB13c | | |------------+--------------------+--------------------| | 12.2MC | 12.2(15)MC2e | | |------------+--------------------+--------------------| | | 12.2(14)S15 | | | |--------------------+--------------------| | | 12.2(18)S10 | | | |--------------------+--------------------| | | 12.2(20)S9 | | | 12.2S |--------------------+--------------------| | | 12.2(25)S6 | | | |--------------------+--------------------| | | 12.2(30)S1, | | | | available | | | | 14-Nov-2005 | | |------------+--------------------+--------------------| | 12.2SBC | | 12.2(27)SBC | |------------+--------------------+--------------------| | | 12.2(25)SEB4 | 12.2(25)SED | | 12.2SE |--------------------+--------------------| | | 12.2(25)SEC2 | | |------------+--------------------+--------------------| | 12.2SG | | 12.2(25)SG | |------------+--------------------+--------------------| | 12.2SO | 12.2(18)SO4 | | |------------+-----------------------------------------| | 12.2SU | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | | 12.2(26)SV1 | | | |--------------------+--------------------| | 12.2SV | 12.2(27)SV1, | | | | available | | | | 15-Nov-2005 | | |------------+--------------------+--------------------| | | | 12.2(25)SW4 | | 12.2SW |--------------------+--------------------| | | | 12.2(25)SW4a | |------------+-----------------------------------------| | 12.2SX | Vulnerable; migrate to 12.2(17d)SXB10 | | | or later | |------------+-----------------------------------------| | 12.2SXA | Vulnerable; migrate to 12.2(17d)SXB10 | | | or later | |------------+-----------------------------------------| | 12.2SXB | 12.2(17d)SXB10 | | |------------+--------------------+--------------------| | 12.2SXD | 12.2(18)SXD6 | | |------------+--------------------+--------------------| | 12.2SXE | 12.2(18)SXE3 | | |------------+--------------------+--------------------| | 12.2SXF | | 12.2(18)SXF | |------------+-----------------------------------------| | 12.2SY | Vulnerable; migrate to 12.2(17d)SXB10 | | | or later | |------------+-----------------------------------------| | 12.2SZ | Vulnerable; migrate to 12.2(25)S6 or | | | later | |------------+-----------------------------------------| | 12.2T | 12.2(15)T17 | | |------------+--------------------+--------------------| | 12.2TPC | 12.2(8)TPC10a, | | | | available TBD | | |------------+-----------------------------------------| | 12.2XA | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XB | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XC | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2XD | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XE | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XF | Vulnerable; migrate to 12.2(15)BC2i or | | | later | |------------+-----------------------------------------| | 12.2XG | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XH | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XI | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XJ | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XK | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XL | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XM | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XN | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XQ | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | | 12.2(2)XR and 12.2(4)XR vulnerable, | | | migrate to 12.3(16) or later | | 12.2XR |-----------------------------------------| | | 12.2(15)XR vulnerable; migrate to 12.3 | | | (7)JA1 | |------------+-----------------------------------------| | 12.2XS | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XT | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XU | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XV | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2XW | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2YA | 12.2(4)YA11, | | | | available TBD | | |------------+-----------------------------------------| | 12.2YB | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2YC | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2YD | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2YE | Vulnerable; migrate to 12.2(25)S6 or | | | later | |------------+-----------------------------------------| | 12.2YF | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2YG | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2YH | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2YJ | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2YK | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2YL | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2YM | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2YN | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2YO | Vulnerable; migrate to 12.2(17d)SXB10 | | | or later | |------------+-----------------------------------------| | 12.2YP | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2YQ | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2YR | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2YS | | 12.2(15)YS | |------------+-----------------------------------------| | 12.2YT | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2YU | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2YV | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2YW | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2YX | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2YY | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2YZ | Vulnerable; migrate to 12.2(25)S6 or | | | later | |------------+-----------------------------------------| | 12.2ZA | Vulnerable; migrate to 12.2(17d)SXB10 | | | or later | |------------+-----------------------------------------| | 12.2ZB | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2ZC | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2ZD | 12.2(13)ZD4 | | |------------+-----------------------------------------| | 12.2ZE | Vulnerable; migrate to 12.3(16) or | | | later | |------------+-----------------------------------------| | 12.2ZF | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | | Vulnerable; migrate to 12.3(8)YG3 or | | 12.2ZG | later for SOHO9x migrate to 12.3(2)XA5 | | | or later for c83x | |------------+-----------------------------------------| | 12.2ZH | 12.2(13)ZH8, | | | | available TBD | | |------------+-----------------------------------------| | 12.2ZJ | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | | Vulnerable; migrate to 12.3(4)XK4 or | | 12.2ZL | later for c17xx migrate to 12.4(3a) or | | | later for c3200 migrate to 12.3(7)XR6 | | | or later for ICS7750 | |------------+-----------------------------------------| | 12.2ZN | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.2ZP | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | Affected | | | | 12.3-Based | Rebuild | Maintenance | | Release | | | |------------+--------------------+--------------------| | | 12.3(3i) | | | |--------------------+--------------------| | | 12.3(5f) | | | |--------------------+--------------------| | | 12.3(6f) | | | |--------------------+--------------------| | | 12.3(9e) | | | 12.3 |--------------------+--------------------| | | 12.3(10e) | | | |--------------------+--------------------| | | 12.3(12e) | | | |--------------------+--------------------| | | 12.3(13b) | | | |--------------------+--------------------| | | 12.3(15b) | 12.3(16) | |------------+-----------------------------------------| | 12.3B | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | | 12.3(9a)BC7 | | | 12.3BC |--------------------+--------------------| | | 12.3(13a)BC1 | | |------------+-----------------------------------------| | 12.3BW | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | | 12.3(2)JA5 | | | |--------------------+--------------------| | 12.3JA | 12.3(4)JA1 | | | |--------------------+--------------------| | | 12.3(7)JA1 | | |------------+--------------------+--------------------| | 12.3JK | 12.3(2)JK1 | | |------------+--------------------+--------------------| | 12.3JX | 12.3(7)JX | | |------------+--------------------+--------------------| | | 12.3(7)T12 | | | |--------------------+--------------------| | | 12.3(8)T11 | | | 12.3T |--------------------+--------------------| | | 12.3(11)T8 | | | |--------------------+--------------------| | | 12.3(14)T4 | | |------------+--------------------+--------------------| | 12.3TPC | 12.3(4)TPC11a | | |------------+--------------------+--------------------| | 12.3XA | 12.3(2)XA5, | | | | available TBD | | |------------+-----------------------------------------| | 12.3XB | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.3XC | 12.3(2)XC4 | | |------------+-----------------------------------------| | 12.3XD | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.3XE | 12.3(4)XE4, | | | | available TBD | | |------------+-----------------------------------------| | 12.3XF | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.3XG | 12.3(4)XG5 | | |------------+-----------------------------------------| | 12.3XH | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | | 12.3(7)XI7, | | | 12.3XI | available | | | | 15-Nov-2005 | | |------------+-----------------------------------------| | 12.3XJ | Vulnerable; migrate to 12.3(11)YF4 or | | | later | |------------+-----------------------------------------| | 12.3XK | 12.3(4)XK4 | | |------------+-----------------------------------------| | 12.3XM | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | 12.3XQ | Vulnerable; migrate to 12.4(3a) or | | | later | |------------+-----------------------------------------| | 12.3XR | 12.3(7)XR6 | | |------------+-----------------------------------------| | 12.3XS | Vulnerable; migrate to 12.4(3a) or | | | later | |------------+-----------------------------------------| | 12.3XU | Vulnerable; migrate to 12.4(2)T1 or | | | later | |------------+-----------------------------------------| | 12.3XW | Vulnerable; migrate to 12.3(11)YF4 or | | | later | |------------+-----------------------------------------| | 12.3XX | Vulnerable; migrate to 12.4(3a) or | | | later | |------------+-----------------------------------------| | 12.3XY | Vulnerable; migrate to 12.3(14)T4 or | | | later | |------------+-----------------------------------------| | | Vulnerable; migrate to 12.4(3a) or | | 12.3YA | later for C828; migrate to 12.3(8)YG3 | | | or later for SOHO9x, C83x | |------------+-----------------------------------------| | 12.3YD | Vulnerable; migrate to 12.4(2)T1 or | | | later | |------------+-----------------------------------------| | 12.3YF | 12.3(11)YF4 | | |------------+--------------------+--------------------| | 12.3YG | 12.3(8)YG3 | | |------------+-----------------------------------------| | 12.3YH | Vulnerable; migrate to 12.3(8)YI3 or | | | later | |------------+-----------------------------------------| | 12.3YI | 12.3(8)YI3 | | |------------+--------------------+--------------------| | 12.3YJ | 12.3(14)YQ3 | | |------------+--------------------+--------------------| | 12.3YK | 12.3(11)YK2 | | |------------+--------------------+--------------------| | 12.3YQ | 12.3(14)YQ3 | | |------------+--------------------+--------------------| | 12.3YS | 12.3(11)YS1 | | |------------+--------------------+--------------------| | 12.3YT | 12.3(14)YT1 | | |------------+--------------------+--------------------| | 12.3YU | 12.3(14)YU1 | | |------------+--------------------+--------------------| | Affected | | | | 12.4-Based | Rebuild | Maintenance | | Release | | | |------------+--------------------+--------------------| | | 12.4(1b) | | | 12.4 |--------------------+--------------------| | | 12.4(3a) | | |------------+--------------------+--------------------| | 12.4MR | | 12.4(2)MR1 | |------------+--------------------+--------------------| | 12.4T | 12.4(2)T1 | | |------------+--------------------+--------------------| | 12.4XA | | 12.4(2)XA | |------------+--------------------+--------------------| | | | 12.4(2)XB, | | 12.4XB | | available | | | | 18-Nov-2005 | +------------------------------------------------------+ Obtaining Fixed Software ======================== 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 agreement with third-party support organizations such as Cisco Partners, authorized resellers, or service providers should contact that support organization for assistance with the upgrade, which should be free of charge. Customers without Service Contracts +---------------------------------- Customers who purchase direct from Cisco but who do not hold a Cisco service contract and customers who purchase through third-party vendors but are unsuccessful at obtaining fixed software through their point of sale should get their upgrades by contacting the Cisco Technical Assistance Center (TAC). TAC contacts are as follows. * +1 800 553 2447 (toll free from within North America) * +1 408 526 7209 (toll call from anywhere in the world) * e-mail: tac@cisco.com Please have your product serial number available and give the URL of this notice as evidence of your entitlement to a free upgrade. Free upgrades for non-contract customers must be requested through the TAC. Please do not contact either "psirt@cisco.com" or "security-alert@cisco.com" for software upgrades. See http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml for additional TAC contact information, including special localized telephone numbers and instructions and e-mail addresses for use in various languages. 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/public/sw-license-agreement.html, or as otherwise set forth at Cisco.com Downloads at http://www.cisco.com/public/sw-center/sw-usingswc.shtml. Workarounds =========== There are no workarounds or configuration changes that will implement counter-measures equivalent to the increased integrity checks on system timers that have been introduced. In order to reduce the potential for system timer-related arbitrary code execution, an IOS upgrade is necessary. Successful exploitation requires an appropriate attack vector such as the vulnerability described in http://www.cisco.com/warp/publics/707/cisco-sa-20050729-ipv6.shtml. Vulnerability specific workarounds and mitigation steps may help to minimize the threat to the device by removing or minimizing the available attack vectors, but the device could still be vulnerable through any other attack vectors in which a software fix or mitigation has not been implemented. Exploitation and Public Announcements ===================================== The Cisco PSIRT is not aware of malicious use of the vulnerability described in this advisory. Exploit code exists for this vulnerability. It was used in a demonstration by Mike Lynn on July 27, 2005 at the Black Hat USA 2005 security conference where a heap overflow via an IPv6 attack vector achieved remote code execution. The IPv6 attack vector was addressed separately in a Cisco security advisory released on July 29, 2005. Status of This Notice: FINAL ============================ THIS ADVISORY IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF THE INFORMATION ON THE ADVISORY OR MATERIALS LINKED FROM THE ADVISORY IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS NOTICE AT ANY TIME. A stand-alone copy or paraphrase of the text of this security advisory 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-20051102-timers.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. * cust-security-announce@cisco.com * first-teams@first.org (includes CERT/CC) * bugtraq@securityfocus.com * vulnwatch@vulnwatch.org * cisco@spot.colorado.edu * cisco-nsp@puck.nether.net * full-disclosure@lists.grok.org.uk * comp.dcom.sys.cisco@newsgate.cisco.com 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 1.0 | 2-Nov-2005 | Initial 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.h.... This includes instructions for press inquiries regarding Cisco security notices. All Cisco security advisories are available at http://www.cisco.com/go/psirt. - ----------------------------------------------------------------------- All contents are Copyright 1992-2005 Cisco Systems, Inc. All rights reserved. - ----------------------------------------------------------------------- Updated: Nov 02, 2005 Document ID: 68064 - ----------------------------------------------------------------------- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQFDaOt+ezGozzK2tZARArUkAKCbXRtfxKZDQ3T5x3NDU09kMiMdgACggaVp BH34hLlTWTtB/YyiMkOhiBY= =qUE2 -----END PGP SIGNATURE-----