-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Cisco Security Advisory: Multiple DLSw Denial of Service Vulnerabilities in Cisco IOS Advisory ID: cisco-sa-20080326-dlsw http://www.cisco.com/warp/public/707/cisco-sa-20080326-dlsw.shtml Revision 1.0 For Public Release 2008 March 26 1600 UTC (GMT) Summary ======= Cisco IOS contains multiple vulnerabilities in the Data-link Switching (DLSw) feature that may result in a reload or memory leaks when processing specially crafted UDP or IP Protocol 91 packets. Cisco has released free software updates that address these vulnerabilities. Workarounds are available to mitigate the effects of these vulnerabilities. This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20080326-dlsw.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. * March 26th bundled IOS Advisory Table http://www.cisco.com/warp/public/707/cisco-sa-20080326-bundle.shtml Individual publication links are listed below: * Cisco IOS Virtual Private Dial-up Network Denial of Service Vulnerability http://www.cisco.com/warp/public/707/cisco-sa-20080326-pptp.shtml * Multiple DLSw Denial of Service Vulnerabilities in Cisco IOS http://www.cisco.com/warp/public/707/cisco-sa-20080326-dlsw.shtml * Cisco IOS User Datagram Protocol Delivery Issue For IPv4/IPv6 Dual-stack Routers http://www.cisco.com/warp/public/707/cisco-sa-20080326-IPv4IPv6.shtml * Vulnerability in Cisco IOS with OSPF, MPLS VPN, and Supervisor 32, Supervisor 720, or Route Switch Processor 720 http://www.cisco.com/warp/public/707/cisco-sa-20080326-queue.shtml * Cisco IOS Multicast Virtual Private Network (MVPN) Data Leak http://www.cisco.com/warp/public/707/cisco-sa-20080326-mvpn.shtml Affected Products ================= Vulnerable Products +------------------ This security advisory applies to all Cisco products that run any version of affected Cisco IOS software configured for DLSw. Systems that contain the DLSw feature, but do not have it enabled, are not affected. Routers enabled for DLSw contain a line in the configuration defining a local DLSw peer. This configuration can be observed by issuing the command "show running-config". Systems configured for DLSw contain lines similar to the following: "dlsw local-peer" or "dlsw local-peer peer-id <IP address>" Any version of Cisco IOS prior to the versions which are listed in the Software Versions and Fixes section below is vulnerable. To determine the version of Cisco IOS 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 Cisco IOS Software Release 12.3(6) with an installed image name of C3640-IS-M: Cisco Internetwork Operating System Software IOS (tm) 3600 Software (C3640-IS-M), Version 12.3(6), RELEASE SOFTWARE (fc3) The next example shows a product running Cisco IOS Software 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. Products Confirmed Not Vulnerable +-------------------------------- Cisco IOS devices that are not configured for DLSw are not vulnerable. No other Cisco products are currently known to be affected by these vulnerabilities. Details ======= Data-link switching (DLSw) provides a means of transporting IBM Systems Network Architecture (SNA) and network basic input/output system (NetBIOS) traffic over an IP network. Cisco implementation of DLSw also uses UDP port 2067 and IP Protocol 91 for Fast Sequenced Transport (FST). Multiple vulnerabilities exists in Cisco IOS when processing UDP and IP protocol 91 packets. These vulnerabilities do not affect TCP packet processing. A successful exploitation may result in a reload of the system or a memory leak on the device, leading to a denial of service (DoS) condition. Cisco IOS devices configured for DLSw with "dlsw local-peer" automatically listen for IP protocol 91 packets. A Cisco IOS device that is configured for DLSw with the "dlsw local-peer peer-id <IP-address>" command listen for IP protocol 91 packets and UDP port 2067. Cisco IOS devices listen to IP protocol 91 packets when DLSw is configured. However, it is only used if DLSw is configured for Fast Sequenced Transport (FST). A DLSw FST peer configuration will contain the following line: "dlsw remote-peer 0 fst <ip-address>" It is possible to disable UDP processing in DLSw with the "dlsw udp-disable" command. However, disabling UDP only prevents the sending of UDP packets, it does not prevent the device from receiving and processing incoming UDP packets. These vulnerabilities are documented in Cisco Bug ID CSCsk73104 and have been assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2008-1152. 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 CSCsk73104 - Handling of malformed packets by DLSW 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 these vulnerabilities may result in the reload of the device or memory leaks, leading to a DoS condition. 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 | | | |------------+-------------+-------------| | | Vulnerable; | | | 12.0 | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.0(8)DA3 | | | | are | | | | vulnerable, | | | | release | | | 12.0DA | 12.0(8)DA3 | | | | and later | | | | are not | | | | vulnerable; | | | | migrate to | | | | any release | | | | in 12.2DA | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.0(7)DB | | | | are | | | | vulnerable, | | | 12.0DB | release | 12.4(18a) | | | 12.0(7)DB | | | | and later | | | | are not | | | | vulnerable; | | | | first fixed | | | | in 12.4 | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.0(7)DC | | | | are | | | | vulnerable, | | | 12.0DC | release | 12.4(18a) | | | 12.0(7)DC | | | | and later | | | | are not | | | | vulnerable; | | | | first fixed | | | | in 12.4 | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.0(17)S5 | | | | are | | | 12.0S | vulnerable, | 12.0(32)S10 | | | release | | | | 12.0(17)S5 | | | | and later | | | | are not | | | | vulnerable; | | |------------+-------------+-------------| | 12.0SC | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.0SL | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.0SP | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.0ST | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.0SX | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.0SY | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.0SZ | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.0T | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | 12.0W | Vulnerable; | 12.0(3c)W5 | | | contact TAC | (8) | |------------+-------------+-------------| | 12.0WC | Vulnerable; | | | | contact TAC | | |------------+-------------+-------------| | 12.0WT | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.0XA | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | 12.0XB | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.0(2)XC2 | | | | are | | | | vulnerable, | | | 12.0XC | release | 12.3(26) | | | 12.0(2)XC2 | | | | and later | | | | are not | | | | vulnerable; | | | | first fixed | | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.0XD | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.0XE | first fixed | | | | in 12.1E | | |------------+-------------+-------------| | 12.0XF | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.0XG | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.0XH | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.0(4)XI2 | | | | are | | | | vulnerable, | | | 12.0XI | release | 12.3(26) | | | 12.0(4)XI2 | | | | and later | | | | are not | | | | vulnerable; | | | | first fixed | | | | in 12.3 | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.0(4)XJ5 | | | | are | | | | vulnerable, | | | 12.0XJ | release | 12.3(26) | | | 12.0(4)XJ5 | | | | and later | | | | are not | | | | vulnerable; | | | | first fixed | | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.0XK | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | 12.0XL | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.0XM | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.0XN | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.0XQ | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.0XR | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | 12.0XS | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.0XV | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.0XW | Not | | | | Vulnerable | | |------------+-------------+-------------| | Affected | First Fixed | Recommended | | 12.1-Based | Release | Release | | Releases | | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1 | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1AA | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | 12.1AX | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.1(22)AY1 | | | | are | | | 12.1AY | vulnerable, | 12.1(22) | | | release | EA11 | | | 12.1(22)AY1 | | | | and later | | | | are not | | | | vulnerable; | | |------------+-------------+-------------| | 12.1AZ | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.1CX | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.1DA | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.1(4)DB1 | | | | are | | | | vulnerable, | | | 12.1DB | release | 12.4(18a) | | | 12.1(4)DB1 | | | | and later | | | | are not | | | | vulnerable; | | | | first fixed | | | | in 12.4 | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.1(4)DC2 | | | | are | | | | vulnerable, | | | 12.1DC | release | 12.4(18a) | | | 12.1(4)DC2 | | | | and later | | | | are not | | | | vulnerable; | | | | first fixed | | | | in 12.4 | | |------------+-------------+-------------| | 12.1E | 12.1(27b)E4 | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.1(11)EA1 | | | | are | | | 12.1EA | vulnerable, | 12.1(22) | | | release | EA11 | | | 12.1(11)EA1 | | | | and later | | | | are not | | | | vulnerable; | | |------------+-------------+-------------| | 12.1EB | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1EC | migrate to | 12.3(23)BC1 | | | any release | | | | in 12.2BC | | |------------+-------------+-------------| | 12.1EO | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.1EU | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.1EV | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.1EW | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1EX | first fixed | | | | in 12.1E | | |------------+-------------+-------------| | 12.1EY | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1EZ | first fixed | | | | in 12.1E | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1GA | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1GB | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1T | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XA | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | 12.1XB | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XC | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XD | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | 12.1XE | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.1XF | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XG | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XH | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XI | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XJ | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | 12.1XK | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.1XL | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XM | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | 12.1XN | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.1XO | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XP | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XQ | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | 12.1XR | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XS | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.1(3)XT2 | | | | are | | | | vulnerable, | | | 12.1XT | release | 12.3(26) | | | 12.1(3)XT2 | | | | and later | | | | are not | | | | vulnerable; | | | | first fixed | | | | in 12.3 | | |------------+-------------+-------------| | 12.1XU | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.1(5)XV1 | | | | are | | | | vulnerable, | | | 12.1XV | release | 12.3(26) | | | 12.1(5)XV1 | | | | and later | | | | are not | | | | vulnerable; | | | | first fixed | | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XW | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XX | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XY | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1XZ | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1YA | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1YB | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | 12.1YC | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.1YD | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.1(5)YE1 | | | | are | | | | vulnerable, | | | 12.1YE | release | 12.3(26) | | | 12.1(5)YE1 | | | | and later | | | | are not | | | | vulnerable; | | | | first fixed | | | | in 12.3 | | |------------+-------------+-------------| | 12.1YF | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.1YG | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.1YH | Not | | | | Vulnerable | | |------------+-------------+-------------| | | 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 | | | |------------+-------------+-------------| | | Vulnerable; | | | 12.2 | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.2B | first fixed | 12.4(18a) | | | in 12.4 | | |------------+-------------+-------------| | 12.2BC | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.2BW | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.2BY | first fixed | 12.4(18a) | | | in 12.4 | | |------------+-------------+-------------| | 12.2BZ | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2CX | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2CY | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2CZ | Not | | | | Vulnerable | | |------------+-------------+-------------| | 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 | | |------------+-------------+-------------| | 12.2EU | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2EW | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2EWA | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.2EX | migrate to | 12.2(40)EX1 | | | any release | | | | in 12.2SEA | | |------------+-------------+-------------| | 12.2EY | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2EZ | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2FX | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2FY | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2FZ | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2IXA | Vulnerable; | | | | contact TAC | | |------------+-------------+-------------| | 12.2IXB | Vulnerable; | | | | contact TAC | | |------------+-------------+-------------| | 12.2IXC | Vulnerable; | | | | contact TAC | | |------------+-------------+-------------| | 12.2IXD | Vulnerable; | | | | contact TAC | | |------------+-------------+-------------| | | Vulnerable; | 12.2(18) | | | migrate to | IXF; | | 12.2IXE | any release | Available | | | in 12.2IXF | on | | | | 31-MAR-08 | |------------+-------------+-------------| | 12.2JA | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2JK | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2MB | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2MC | 12.2(15) | 12.4(18a) | | | MC2h | | |------------+-------------+-------------| | 12.2S | 12.2(25)S15 | 12.2(25)S15 | |------------+-------------+-------------| | | 12.2(28) | | | | SB10 | | | | | | | | 12.2(31)SB9 | 12.2(28) | | 12.2SB | | SB12 | | | 12.2(33)SB; | | | | Available | | | | on | | | | 31-MAR-08 | | |------------+-------------+-------------| | | Vulnerable; | | | | first fixed | | | | in 12.2SB | | | | | | | 12.2SBC | Vulnerable; | 12.2(28) | | | first fixed | SB12 | | | in 12.2SB; | | | | Available | | | | on | | | | 31-MAR-08 | | |------------+-------------+-------------| | 12.2SCA | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SE | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SEA | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SEB | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SEC | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SED | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SEE | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SEF | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SEG | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SG | 12.2(44)SG | 12.2(44)SG | |------------+-------------+-------------| | 12.2SGA | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SL | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SM | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SO | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SRA | 12.2(33) | 12.2(33) | | | SRA6 | SRA7 | |------------+-------------+-------------| | | 12.2(33) | 12.2(33) | | | SRB3; | SRB3; | | 12.2SRB | Available | Available | | | on | on | | | 31-MAR-08 | 31-MAR-08 | |------------+-------------+-------------| | 12.2SRC | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.2SU | first fixed | 12.4(18a) | | | in 12.4 | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.2(29a) | | | | SV1 are | | | | vulnerable, | | | | release | | | 12.2SV | 12.2(29a) | 12.2(29b)SV | | | SV1 and | | | | later are | | | | not | | | | vulnerable; | | | | migrate to | | | | any release | | | | in 12.2SVA | | |------------+-------------+-------------| | 12.2SVA | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SVC | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2SVD | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.2(25) | | | | SW10 are | | | | vulnerable, | | | 12.2SW | release | | | | 12.2(25) | | | | SW10 and | | | | later are | | | | not | | | | vulnerable; | | |------------+-------------+-------------| | | 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) | | | | SXF12 | | | | | | | 12.2SXF | 12.2(18) | 12.2(18) | | | SXF12a | SXF13 | | | | | | | 12.2(18) | | | | SXF13a | | |------------+-------------+-------------| | 12.2SXH | 12.2(33) | | | | SXH1 | | |------------+-------------+-------------| | | 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) | | | | TPC10d | | |------------+-------------+-------------| | 12.2UZ | Not | | | | Vulnerable | | |------------+-------------+-------------| | | 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 | | |------------+-------------+-------------| | 12.2XE | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2XF | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.2XG | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.2XH | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | 12.2XI | Not | | | | Vulnerable | | |------------+-------------+-------------| | | 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 | | |------------+-------------+-------------| | 12.2XR | Not | | | | Vulnerable | | |------------+-------------+-------------| | 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 | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.2(4)YA8 | | | | are | | | | vulnerable, | | | 12.2YA | release | 12.3(26) | | | 12.2(4)YA8 | | | | and later | | | | are not | | | | vulnerable; | | | | first fixed | | | | in 12.3 | | |------------+-------------+-------------| | | 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 | | |------------+-------------+-------------| | 12.2YG | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.2YH | first fixed | 12.3(26) | | | in 12.3 | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.2(8)YJ1 | | | | are | | | | vulnerable, | | | 12.2YJ | release | 12.3(26) | | | 12.2(8)YJ1 | | | | and later | | | | are not | | | | vulnerable; | | | | first fixed | | | | in 12.3 | | |------------+-------------+-------------| | 12.2YK | Not | | | | Vulnerable | | |------------+-------------+-------------| | | 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 | | |------------+-------------+-------------| | 12.2YP | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2YQ | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.2YR | Not | | | | Vulnerable | | |------------+-------------+-------------| | 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 | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.2(11)YV1 | | | | are | | | | vulnerable, | | | 12.2YV | release | 12.4(18a) | | | 12.2(11)YV1 | | | | and later | | | | are not | | | | vulnerable; | | | | first fixed | | | | 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 | | |------------+-------------+-------------| | 12.2ZC | Not | | | | Vulnerable | | |------------+-------------+-------------| | 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 | | |------------+-------------+-------------| | 12.2ZG | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.2(13)ZH6 | | | | are | | | | vulnerable, | | | 12.2ZH | release | 12.2(13) | | | 12.2(13)ZH6 | ZH11 | | | and later | | | | are not | | | | vulnerable; | | | | first fixed | | | | in 12.4 | | |------------+-------------+-------------| | | 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) | |------------+-------------+-------------| | 12.2ZP | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | 12.2(33) | | 12.2ZU | first fixed | SXH2 | | | in 12.2SXH | | |------------+-------------+-------------| | 12.2ZY | 12.2(18)ZY2 | 12.2(18)ZY2 | |------------+-------------+-------------| | Affected | First Fixed | Recommended | | 12.3-Based | Release | Release | | Releases | | | |------------+-------------+-------------| | 12.3 | 12.3(24) | 12.3(26) | |------------+-------------+-------------| | | Vulnerable; | | | 12.3B | first fixed | 12.4(18a) | | | in 12.4 | | |------------+-------------+-------------| | 12.3BC | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.3BW | first fixed | 12.4(18a) | | | in 12.4 | | |------------+-------------+-------------| | 12.3EU | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.3JA | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.3JEA | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.3JEB | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.3JEC | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Releases | | | | prior to | | | | 12.3(8)JK1 | | | | are | | | 12.3JK | vulnerable, | 12.3(8)JK1 | | | release | | | | 12.3(8)JK1 | | | | and later | | | | are not | | | | vulnerable; | | |------------+-------------+-------------| | 12.3JL | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.3JX | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | | | 12.3T | first fixed | 12.4(18a) | | | in 12.4 | | |------------+-------------+-------------| | 12.3TPC | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.3VA | Vulnerable; | | | | contact TAC | | |------------+-------------+-------------| | | 12.3(2)XA7; | 12.3(2)XA7; | | 12.3XA | Available | Available | | | on | on | | | 31-MAR-08 | 31-MAR-08 | |------------+-------------+-------------| | | 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-08 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.3XF | first fixed | 12.4(18a) | | | in 12.4 | | |------------+-------------+-------------| | | Vulnerable; | | | | first fixed | 12.4(15)T4 | | 12.3XG | in 12.3YG; | | | | Available | 12.4(18a) | | | on | | | | 16-JUN-08 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.3XH | first fixed | 12.4(18a) | | | in 12.4 | | |------------+-------------+-------------| | | 12.3(7) | | | | XI11; | | | 12.3XI | Available | | | | on | | | | 18-SEP-08 | | |------------+-------------+-------------| | | 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; | 12.3(7)XR8; | | 12.3XR | Available | Available | | | on | on | | | 31-MAR-08 | 31-MAR-08 | |------------+-------------+-------------| | 12.3XS | Not | | | | Vulnerable | | |------------+-------------+-------------| | | 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 | |------------+-------------+-------------| | 12.3XY | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.3YA | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.3YD | Not | | | | Vulnerable | | |------------+-------------+-------------| | | Vulnerable; | 12.3(14) | | 12.3YF | first fixed | YX11 | | | in 12.3YX | | | | | 12.4(15)T4 | |------------+-------------+-------------| | | 12.3(8)YG7; | | | 12.3YG | Available | 12.4(15)T4 | | | on | | | | 16-JUN-08 | | |------------+-------------+-------------| | | 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 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.3YK | first fixed | 12.4(15)T4 | | | in 12.4T | | |------------+-------------+-------------| | 12.3YM | 12.3(14) | 12.3(14) | | | YM12 | 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-08 | | |------------+-------------+-------------| | | 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) | 12.3(14) | | | YX11 | YX11 | |------------+-------------+-------------| | 12.3YZ | 12.3(11)YZ3 | | |------------+-------------+-------------| | Affected | First Fixed | Recommended | | 12.4-Based | Release | Release | | Releases | | | |------------+-------------+-------------| | | 12.4(10c) | | | | | | | | 12.4(13e) | | | | | | | | 12.4(16b) | | | 12.4 | | 12.4(18a) | | | 12.4(17) | | | | | | | | 12.4(3h) | | | | | | | | 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 | | |------------+-------------+-------------| | | 12.4(15)MD; | | | 12.4MD | Available | | | | on | | | | 09-MAY-08 | | |------------+-------------+-------------| | 12.4MR | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.4SW | Vulnerable; | | | | contact TAC | | |------------+-------------+-------------| | | 12.4(15)T2 | | | | | | | 12.4T | 12.4(6)T10 | 12.4(15)T4 | | | | | | | 12.4(9)T7 | | |------------+-------------+-------------| | | Vulnerable; | | | 12.4XA | first fixed | 12.4(15)T4 | | | in 12.4T | | |------------+-------------+-------------| | 12.4XB | 12.4(2)XB6 | | |------------+-------------+-------------| | 12.4XC | Vulnerable; | | | | contact TAC | | |------------+-------------+-------------| | 12.4XD | 12.4(4)XD10 | 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 | |------------+-------------+-------------| | | Vulnerable; | | | 12.4XJ | first fixed | 12.4(15)T4 | | | in 12.4T | | |------------+-------------+-------------| | | Vulnerable; | | | 12.4XK | first fixed | 12.4(15)T4 | | | in 12.4T | | |------------+-------------+-------------| | 12.4XL | 12.4(15)XL2 | | |------------+-------------+-------------| | 12.4XM | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.4XN | Not | | | | Vulnerable | | |------------+-------------+-------------| | 12.4XT | 12.4(6)XT2 | 12.4(6)XT2 | |------------+-------------+-------------| | 12.4XV | 12.4(11)XV | | |------------+-------------+-------------| | 12.4XW | Vulnerable; | 12.4(11)XW6 | | | contact TAC | | |------------+-------------+-------------| | 12.4XY | Not | | | | Vulnerable | | +----------------------------------------+ A special patch for Cisco IOS Software Modularity is also available and can be downloaded from the Cisco IOS Software Modularity Patch Navigator at http://tools.cisco.com/swdf/ionpn/jsp/main.jsp. Workarounds =========== The workaround consists of filtering UDP packets to port 2067 and IP protocol 91 packets. Filters can be applied at network boundaries to filter all IP protocol 91 packets and UDP packets to port 2067 or can be applied on individual affected devices to permit such traffic only from trusted peer IP addresses. However, since both of the protocols are connectionless, it is possible for an attacker to spoof malformed packets from legitimate peer IP addresses. As soon as DLSw is configured, the Cisco IOS device begins listening on IP protocol 91. However, this protocol is only used if DLSw is configured for Fast Sequenced Transport (FST). A DLSw FST peer configuration will contain the following line: "dlsw remote-peer 0 fst <ip-address>" If FST is used, filtering IP protocol 91 will break the operation, so filters need to permit protocol 91 traffic from legitimate peer IP addresses. It is possible to disable UDP processing in DLSw with the "dlsw udp-disable" command. However, disabling UDP only prevents the sending of UDP packets, it does not prevent the receiving and processing of incoming UDP packets. To protect a vulnerable device from malicious packets via UDP port 2067, both of the following actions must be taken: 1. Disable UDP outgoing packets with the "dlsw udp-disable" command, AND 2. Filter UDP 2067 in the vulnerable device using infrastructure ACL. 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-dlsw.shtml Using Control Plane Policing on Affected Devices +----------------------------------------------- Control Plane Policing (CoPP) can be used to block untrusted DLSw traffic to the device. Cisco IOS software releases 12.0S, 12.2SX, 12.2S, 12.3T, 12.4, and 12.4T support the CoPP feature. CoPP may be configured on a device to protect the management and control planes to minimize the risk and effectiveness of direct infrastructure attacks by explicitly permitting only authorized traffic sent to infrastructure devices in accordance with existing security policies and configurations. The following example, which uses 192.168.100.1 to represent a trusted host, can be adapted to your network. If FST is not used, protocol 91 may be completely filtered. Additionally, if UDP is disabled with the "dlsw udp-disable" command, UDP port 2067 may also be completely filtered. !--- Deny DLSw traffic from trusted hosts to all IP addresses !--- configured on all interfaces of the affected device so that !--- it will be allowed by the CoPP feature access-list 111 deny udp host 192.168.100.1 any eq 2067 access-list 111 deny 91 host 192.168.100.1 any !--- Permit all other DLSw traffic sent to all IP addresses !--- configured on all interfaces of the affected device so that it !--- will be policed and dropped by the CoPP feature access-list 111 permit udp any any eq 2067 access-list 111 permit 91 any any !--- Permit (Police or Drop)/Deny (Allow) all other Layer 3 and Layer 4 !--- traffic in accordance with existing security policies and !--- configurations for traffic that is authorized to be sent !--- to infrastructure devices !--- Create a Class-Map for traffic to be policed by !--- the CoPP feature class-map match-all drop-DLSw-class match access-group 111 !--- Create a Policy-Map that will be applied to the !--- Control-Plane of the device. policy-map drop-DLSw-traffic class drop-DLSw-class drop !--- Apply the Policy-Map to the Control-Plane of the !--- device control-plane service-policy input drop-DLSw-traffic In the above CoPP example, the access control entries (ACEs) which match the potential exploit packets with the "permit" action result in these packets being discarded by the policy-map "drop" function, while packets that match the "deny" action (not shown) are not affected by the policy-map drop function. Please note that in the Cisco IOS 12.2S and 12.0S trains the policy-map syntax is different: policy-map drop-DLSw-traffic class drop-DLSw-class police 32000 1500 1500 conform-action drop exceed-action drop Additional information on the configuration and use of the CoPP feature is available at http://www.cisco.com/en/US/products/ps6642/products_white_paper0900aecd804fa... and http://www.cisco.com/en/US/products/sw/iosswrel/ps1838/products_feature_guid.... Using Infrastructure ACLs at Network Boundary +-------------------------------------------- Although it is often difficult to block traffic transiting your network, it is possible to identify traffic that should never be allowed to target your infrastructure devices and block that traffic at the border of your network. iACLs are a network security best practice and should be considered as a long-term addition to good network security as well as a workaround for this specific vulnerability. The iACL example shown below should be included as part of the deployed infrastructure access-list that will protect all devices with IP addresses in the infrastructure IP address range. If FST is not used, protocol 91 may be completely filtered. Additionally, if UDP is disabled with the "dlsw udp-disable" command, UDP port 2067 may also be completely filtered. !--- Permit DLSw (UDP port 2067 and IP protocol 91) packets !--- from trusted hosts destined to infrastructure addresses. access-list 150 permit udp TRUSTED_HOSTS MASK INFRASTRUCTURE_ADDRESSES MASK eq 2067 access-list 150 permit 91 TRUSTED_HOSTS MASK INFRASTRUCTURE_ADDRESSES MASK !--- Deny DLSw (UDP port 2067 and IP protocol 91) packets from !--- all other sources destined to infrastructure addresses. access-list 150 deny udp any INFRASTRUCTURE_ADDRESSES MASK eq 2067 access-list 150 deny 91 any INFRASTRUCTURE_ADDRESSES MASK !--- Permit/deny all other Layer 3 and Layer 4 traffic in accordance !--- with existing security policies and configurations !--- Permit all other traffic to transit the device. access-list 150 permit ip any any interface serial 2/0 ip access-group 150 in The white paper entitled "Protecting Your Core: Infrastructure Protection Access Control Lists" presents guidelines and recommended deployment techniques for infrastructure protection access lists. This white paper can be obtained at the following link: http://www.cisco.com/en/US/tech/tk648/tk361/technologies_white_paper09186a00... Obtaining Fixed Software ======================== Cisco has released free software updates that address these vulnerabilities. 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.htm... or as otherwise set forth at Cisco.com Downloads at http://www.cisco.com/public/sw-center/sw-usingswc.shtml. Do not contact psirt@cisco.com or security-alert@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. * +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 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. These vulnerabilities were found internally. 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-dlsw.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 * 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 | | 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.h.... This includes instructions for press inquiries regarding Cisco security notices. All Cisco security advisories are available at http://www.cisco.com/go/psirt. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.8 (Darwin) iEYEARECAAYFAkfqS64ACgkQ86n/Gc8U/uD2DwCgloXg5P1/99amiSHmfy+hWxw4 j3YAnjEDUj724NtdpJQcDw2Ui4pKwu01 =ufq4 -----END PGP SIGNATURE-----