-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Cisco Security Advisory: Cisco IOS Software Crafted Encryption Packet Denial of Service Vulnerability Advisory ID: cisco-sa-20090923-tls Revision 1.0 For Public Release 2009 September 23 +--------------------------------------------------------------------- Summary ======= Cisco IOS� Software contains a vulnerability that could allow an attacker to cause a Cisco IOS device to reload by remotely sending a crafted encryption packet. Cisco has released free software updates that address this vulnerability. This advisory is posted at: http://www.cisco.com/warp/public/707/cisco-sa-20090923-tls.shtml Note: The September 23, 2009, Cisco IOS Security Advisory bundled publication includes eleven Security Advisories. Ten of the advisories address vulnerabilities in Cisco IOS Software, and one advisory addresses a vulnerability in Cisco Unified Communications Manager. Each advisory lists the releases that correct the vulnerability or vulnerabilities detailed in the advisory. The following table lists releases that correct all Cisco IOS Software vulnerabilities that have been published on September 23, 2009, or earlier. http://www.cisco.com/warp/public/707/cisco-sa-20090923-bundle.shtml Individual publication links are in "Cisco Event Response: Semiannual Cisco IOS Software Advisory Bundled Publication" at the following link: http://www.cisco.com/web/about/security/intelligence/Cisco_ERP_sep09.html Affected Products ================= Vulnerable Products +------------------ Devices running affected versions of Cisco IOS Software are susceptible if configured with any of the following features: * Secure Socket Layer (SSL) Virtual Private Network (VPN) * Secure Shell (SSH) * Internet Key Exchange (IKE) Encrypted Nonces Note: Other SSL/HTTPS related features than WebVPN and SSL VPN are not affected by this vulnerability. To determine whether SSLVPN is enabled on a device, log in to the device and issue the command-line interface (CLI) command "show running-config | include webvpn". If the device returns any output then SSLVPN is configured and the device may be vulnerable. Vulnerable configurations vary depending on whether the device is supporting Cisco IOS WebVPN (introduced in Release 12.3(14)T) or Cisco IOS SSLVPNs (introduced in Release 12.4(6)T). The following methods describe how to confirm if the device is vulnerable: If the output from "show running-config | include webvpn" contains "webvpn enable" then the device is configured with the original Cisco IOS WebVPN. The only way to determine whether the device is vulnerable is to examine the output of "show running-config" to confirm that webvpn is enabled via the command "webvpn enable" and that a "ssl trustpoint" has been configured. The following example shows a vulnerable device configured with Cisco IOS WebVPN: webvpn enable ! webvpn ssl trustpoint TP-self-signed-29742012 If the output from "show running-config | include webvpn" contains "webvpn gateway <word>" then the device is supporting the Cisco IOS SSLVPN feature. A device is vulnerable if it has the "inservice" command in at least one of the "webvpn gateway" sections. The following example shows a vulnerable device configured with Cisco IOS SSLVPN: Router# show running | section webvpn webvpn gateway Gateway ip address 10.1.1.1 port 443 ssl trustpoint Gateway-TP inservice ! Router# A device that supports the Cisco IOS SSLVPN is not vulnerable if it has no "webvpn gateways" configured or all the configured "webvpn gateways" contain the "no inservice" webvpn gateway command. To determine if SSH is enabled use the "show ip ssh" command, as shown in the following example: Router#show ip ssh SSH Enabled - version 1.99 Authentication timeout: 120 secs; Authentication retries: 3 Minimum expected Diffie Hellman key size : 1024 bits To determine if the IKE encrypted nonces feature is enabled, use the "show running-config | include rsa-encr" command as follows: Router#show running-config | inc rsa-encr authentication rsa-encr To determine the Cisco IOS Software release that is running on a Cisco product, administrators can log in to the device and issue the show version command to display the system banner. The system banner confirms that the device is running Cisco IOS Software by displaying text similar to "Cisco Internetwork Operating System Software" or "Cisco IOS Software." The image name displays in parentheses, followed by "Version" and the Cisco IOS Software release name. Other Cisco devices do not have the show version command or may provide different output. The following example identifies a Cisco product that is running Cisco IOS Software Release 12.3(26) with an installed image name of C2500-IS-L: Router#show version Cisco Internetwork Operating System Software IOS (tm) 2500 Software (C2500-IS-L), Version 12.3(26), RELEASE SOFTWARE (fc2) Technical Support: http://www.cisco.com/techsupport Copyright (c) 1986-2008 by cisco Systems, Inc. Compiled Mon 17-Mar-08 14:39 by dchih !--- output truncated The following example identifies a Cisco product that is running Cisco IOS Software Release 12.4(20)T with an installed image name of C1841-ADVENTERPRISEK9-M: Router#show version Cisco IOS Software, 1841 Software (C1841-ADVENTERPRISEK9-M), Version 12.4(20)T, RELEASE SOFTWARE (fc3) Technical Support: http://www.cisco.com/techsupport Copyright (c) 1986-2008 by Cisco Systems, Inc. Compiled Thu 10-Jul-08 20:25 by prod_rel_team !--- output truncated Additional information about Cisco IOS Software release naming conventions is available in "White Paper: Cisco IOS Reference Guide" at the following link: http://www.cisco.com/warp/public/620/1.html Products Confirmed Not Vulnerable +-------------------------------- The Cisco ASA 5500 Series Adaptive Security Appliances are not affected by this vulnerability. Cisco IOS XR Software is not affected by this vulnerability. No other Cisco products are currently known to be affected by this vulnerability. Details ======= A Cisco IOS device that is configured for SSLVPN or SSH may reload when it receives a specially crafted TCP packet on TCP port 443 (SSLVPN) or TCP port 22 (SSH). Completion of the three-way handshake to the associated TCP port number of these features is required for the vulnerability to be successfully exploited; however, authentication is not required. A Cisco IOS device that is configured for IKE encrypted nonces may reload when it receives a specially crafted UDP packet on port 500 or 4500 (if configured for NAT Traversal (NAT-T)). This vulnerability is documented in Cisco bug ID CSCsq24002 and has been assigned the Common Vulnerabilities and Exposures (CVE) identifier CVE-2009-2871. Vulnerability Scoring Details ============================= Cisco has provided scores for the vulnerability 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 CSCsq24002 - Crafted Encrypted packet may cause device reload CVSS Base Score - 7.8 Access Vector - Network Access Complexity - Low Authentication - None Confidentiality Impact - None Integrity Impact - None Availability Impact - Complete CVSS Temporal Score - 6.4 Exploitability - Functional Remediation Level - Official-Fix Report Confidence - Confirmed Impact ====== Successful exploitation of the vulnerability described in this document may result in a reload of the device. The issue could be repeatedly exploited to cause an extended 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 Releases | | Release | | |------------+------------------------------------------------------| | Affected | | Recommended | | 12.0-Based | First Fixed Release | Release | | Releases | | | |-------------------------------------------------------------------| | There are no affected 12.0 based releases. | |-------------------------------------------------------------------| | Affected | | Recommended | | 12.1-Based | First Fixed Release | Release | | Releases | | | |-------------------------------------------------------------------| | There are no affected 12.1 based releases. | |-------------------------------------------------------------------| | Affected | | Recommended | | 12.2-Based | First Fixed Release | Release | | Releases | | | |------------+----------------------------------------+-------------| | 12.2 | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2B | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2BC | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2BW | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2BX | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2BY | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2BZ | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2CX | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2CY | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2CZ | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2DA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2DD | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2DX | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2EW | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2EWA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2EX | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2EY | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2EZ | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2FX | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2FY | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2FZ | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2IRA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2IRB | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2IRC | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2IXA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2IXB | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2IXC | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2IXD | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2IXE | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2IXF | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2IXG | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2IXH | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2JA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2JK | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2MB | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2MC | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2S | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SB | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SBC | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SCA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SCB | 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 | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SGA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SL | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SM | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SO | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SQ | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SRA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SRB | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SRC | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SRD | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2STE | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SU | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SV | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SVA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SVC | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SVD | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SVE | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SW | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SX | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SXA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SXB | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SXD | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SXE | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SXF | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SXH | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SXI | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SY | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2SZ | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2T | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2TPC | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XB | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XC | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XD | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XE | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XF | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XG | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XH | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XI | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XJ | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XK | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XL | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XM | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XNA | Please see Cisco IOS-XE Software | | | | Availability | | |------------+----------------------------------------+-------------| | 12.2XNB | Please see Cisco IOS-XE Software | | | | Availability | | |------------+----------------------------------------+-------------| | 12.2XNC | Please see Cisco IOS-XE Software | | | | Availability | | |------------+----------------------------------------+-------------| | 12.2XND | Please see Cisco IOS-XE Software | | | | Availability | | |------------+----------------------------------------+-------------| | 12.2XO | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XQ | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XR | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XS | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XT | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XU | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XV | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2XW | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YB | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YC | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YD | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YE | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YF | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YG | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YH | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YJ | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YK | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YL | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YM | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YN | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YO | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YP | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YQ | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YR | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YS | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YT | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YU | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YV | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YW | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YX | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YY | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2YZ | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZB | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZC | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZD | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZE | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZF | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZG | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZH | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZJ | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZL | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZP | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZU | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZX | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZY | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.2ZYA | Not Vulnerable | | |------------+----------------------------------------+-------------| | Affected | | Recommended | | 12.3-Based | First Fixed Release | Release | | Releases | | | |-------------------------------------------------------------------| | There are no affected 12.3 based releases. | |-------------------------------------------------------------------| | Affected | | Recommended | | 12.4-Based | First Fixed Release | Release | | Releases | | | |------------+----------------------------------------+-------------| | 12.4 | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4GC | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4JA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4JDA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4JDC | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4JDD | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4JK | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4JL | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4JMA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4JMB | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4JX | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4MD | 12.4(15)MD3 | 12.4(15)MD3 | |------------+----------------------------------------+-------------| | 12.4MDA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4MR | 12.4(19)MR3 | 12.4(19)MR3 | |------------+----------------------------------------+-------------| | | | 12.4(15)T10 | | 12.4SW | Vulnerable; first fixed in 12.4T | | | | | 12.4(20)T4 | |------------+----------------------------------------+-------------| | | 12.4(22)T2 | | | | | 12.4(15)T10 | | 12.4T | 12.4(20)T3 | | | | | 12.4(20)T4 | | | 12.4(24)T | | |------------+----------------------------------------+-------------| | 12.4XA | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4XB | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4XC | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4XD | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4XE | Not Vulnerable | | |------------+----------------------------------------+-------------| | | | 12.4(15)T10 | | 12.4XF | Vulnerable; first fixed in 12.4T | | | | | 12.4(20)T4 | |------------+----------------------------------------+-------------| | 12.4XG | Not Vulnerable | | |------------+----------------------------------------+-------------| | | | 12.4(15)T10 | | 12.4XJ | Vulnerable; first fixed in 12.4T | | | | | 12.4(20)T4 | |------------+----------------------------------------+-------------| | | | 12.4(15)T10 | | 12.4XK | Vulnerable; first fixed in 12.4T | | | | | 12.4(20)T4 | |------------+----------------------------------------+-------------| | 12.4XL | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4XM | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4XN | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4XP | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4XQ | 12.4(15)XQ3 | 12.4(15)T10 | |------------+----------------------------------------+-------------| | | | 12.4(15)XR7 | | 12.4XR | 12.4(15)XR5 | | | | | 12.4(22)XR | |------------+----------------------------------------+-------------| | 12.4XT | Not Vulnerable | | |------------+----------------------------------------+-------------| | | Vulnerable; Contact your support | | | 12.4XV | organization per the instructions in | | | | Obtaining Fixed Software section of | | | | this advisory | | |------------+----------------------------------------+-------------| | | | 12.4(15)T10 | | 12.4XW | Vulnerable; first fixed in 12.4T | | | | | 12.4(20)T4 | |------------+----------------------------------------+-------------| | | | 12.4(15)T10 | | 12.4XY | Vulnerable; first fixed in 12.4T | | | | | 12.4(20)T4 | |------------+----------------------------------------+-------------| | | | 12.4(15)T10 | | 12.4XZ | Vulnerable; first fixed in 12.4T | | | | | 12.4(20)T4 | |------------+----------------------------------------+-------------| | | | 12.4(15)T10 | | 12.4YA | Vulnerable; first fixed in 12.4T | | | | | 12.4(20)T4 | |------------+----------------------------------------+-------------| | 12.4YB | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4YD | Not Vulnerable | | |------------+----------------------------------------+-------------| | 12.4YE | Not Vulnerable | | +-------------------------------------------------------------------+ Note: No Cisco IOS Software Modularity releases are affected by this vulnerability. Cisco IOS XE Software +-------------------------------------------------------------------+ | IOS XE Release | First Fixed Release | |----------------------------+--------------------------------------| | 2.1.x | Not Vulnerable | |----------------------------+--------------------------------------| | 2.2.x | Not Vulnerable | |----------------------------+--------------------------------------| | 2.3.x | 2.3.2 | |----------------------------+--------------------------------------| | 2.4.x | Not Vulnerable | +-------------------------------------------------------------------+ Workarounds =========== There are no available workarounds other than disabling the affected features and protecting SSH access with the use of VTY access control lists. Use the "no webvpn enable" command to disable SSL VPN use. For Cisco IOS the SSH server can be disabled by applying the command "crypto key zeroize rsa" while in configuration mode. The SSH server is enabled automatically upon generating an RSA key pair. Zeroing the RSA keys is the only way to completely disable the SSH server. Access to the SSH server on Cisco IOS Software may also be disabled by removing SSH as a valid transport protocol. This action can be done by reapplying the transport input command with 'ssh' removed from the list of permitted transports on vty lines while in configuration mode. For example: line vty 0 4 transport input telnet end If SSH server functionality is desired, access to the server can be restricted to specific source IP addresses or blocked entirely through the use of Access Control Lists (ACLs) on the vty lines as shown in the following URL: http://www.cisco.com/en/US/docs/switches/lan/catalyst2950/software/release/1... More information on configuring ACLs can be found on Cisco's public website: http://www.cisco.com/en/US/products/sw/secursw/ps1018/products_tech_note0918... The following is an example of a vty access-list: access-list 2 permit 10.1.1.0 0.0.0.255 access-list 2 deny any line vty 0 4 access-class 2 in In the previous example, only the 10.1.1.0/24 network is allowed to SSH to the Cisco IOS device. To disable IKE encrypted nonces use the "no authentication rsa-encr" command under an ISAKMP policy, as shown in the following example: crypto isakmp policy no authentication rsa-encr 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/docs/general/warranty/English/EU1KEN_.html or as otherwise set forth at Cisco.com Downloads at: http://www.cisco.com/public/sw-center/sw-usingswc.shtml Do not contact psirt@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/en/US/support/tsd_cisco_worldwide_contacts.html for additional TAC contact information, including localized telephone numbers, and instructions and e-mail addresses for use in various languages. Exploitation and Public Announcements ===================================== The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability described in this advisory. This vulnerability was found during internal testing. 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-20090923-tls.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-bulletins@lists.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 | 2009-September-23 | 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----- iD8DBQFKukGd86n/Gc8U/uARAltxAJsHsWKROOB5Ph8mcFs+ZUIYygRoEgCePeZX A9ezksakGzQynAYZbBjJ+uE= =n8Uh -----END PGP SIGNATURE-----