-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Cisco Security Advisory: Cisco IOS Software Object-group Access Control List Bypass Vulnerability Advisory ID: cisco-sa-20090923-acl Revision 1.0 For Public Release 2009 September 23 +--------------------------------------------------------------------- Summary ======= A vulnerability exists in Cisco IOS� software where an unauthenticated attacker could bypass access control policies when the Object Groups for Access Control Lists (ACLs) feature is used. Cisco has released free software updates that address this vulnerability. There are no workarounds for this vulnerability other than disabling the Object Groups for ACLs feature. This advisory is posted at: http://www.cisco.com/warp/public/707/cisco-sa-20090923-acl.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 +------------------ Any Cisco device configured with ACLs using the object group feature and running an affected Cisco IOS software version is affected by this vulnerability. Note: The Object Groups for ACLs feature was introduced in Cisco IOS software version 12.4(20)T. To verify whether object groups are configured in a Cisco IOS device, use the "show object-group" command in user EXEC or privileged EXEC mode. The following example displays a sample output from the "show object-group" command when object groups are configured: Router# show object-group Network object group my_host_group host 172.18.104.123 Service object group my_allowed_services tcp eq www tcp eq 443 Alternatively, administrators can also use the "show running config | include ^ (permit|deny) .*object-group" command to verify whether object groups are configured, as shown in the following example: Router#show running-config | include ^ (permit|deny) .*object-group permit object-group my_allowed_services host 10.10.1.1 host 10.20.1.1 permit tcp any object-group my_host_group eq 22 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 Products Confirmed Not Vulnerable +-------------------------------- Cisco devices that are not configured with object groups are not vulnerable. Cisco IOS XE Software and Cisco IOS XR Software are not affected by this vulnerability. No other Cisco products are currently known to be affected by this vulnerability. Details ======= In Cisco IOS Software an object group can contain a single object (such as a single IP address, network, or subnet) or multiple objects (such as a combination of multiple IP addresses, networks, or subnets). In an ACL that is based on an object group, administrators can create a single access control entry (ACE) that uses an object group name instead of creating many ACEs, which each would require a different IP address. A similar object group, such as a protocol port group, can be extended to limit access to a set of applications for a user group to a server group. A vulnerability exists in Cisco IOS Software that could allow an unauthenticated attacker to bypass access control policies when the Object Groups for ACLs feature is used. Note: The Object Groups for ACLs feature was introduced in Cisco IOS software version 12.4(20)T. This vulnerability is documented in the following Cisco Bug IDs: * CSCsx07114 * CSCsu70214 * CSCsw47076 * CSCsv48603 * CSCsy54122 * CSCsu50252 This vulnerability has been assigned Common Vulnerabilities and Exposures (CVE) identifier CVE-2009-2862. 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 CSCsx07114, CSCsu70214, CSCsw47076, CSCsv48603, CSCsy54122, CSCsu50252 - Object-group Access Control List Bypass CVSS Base Score - 4.3 Access Vector - Network Access Complexity - Medium Authentication - None Confidentiality Impact - Parital Integrity Impact - None Availability Impact - none CVSS Temporal Score - 3.6 Exploitability - Functional Remediation Level - Official-Fix Report Confidence - Confirmed Impact ====== Successful exploitation of the vulnerability may allow an attacker to access resources that should be protected by the Cisco IOS device. 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 | | | |-------------------------------------------------------------------| | There are no affected 12.1 based releases. | |-------------------------------------------------------------------| | 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 | | |------------+---------------------------------------+--------------| | | Vulnerable; Contact your support | | | 12.4GC | organization per the instructions in | | | | Obtaining Fixed Software section of | | | | this advisory | | |------------+---------------------------------------+--------------| | 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 | | |------------+---------------------------------------+--------------| | | | 12.4(11)MD9 | | | | | | 12.4MD | 12.4(22)MD1 | 12.4(15)MD3 | | | | | | | | 12.4(22)MD1 | |------------+---------------------------------------+--------------| | 12.4MDA | 12.4(22)MDA1 | 12.4(22)MDA1 | |------------+---------------------------------------+--------------| | 12.4MR | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4SW | Not Vulnerable | | |------------+---------------------------------------+--------------| | | | 12.4(20)T4 | | | 12.4(22)T2 | | | | | 12.4(22)T3 | | 12.4T | 12.4(20)T4 | | | | | 12.4(24)T2; | | | 12.4(24)T1 | Available on | | | | 23-OCT-2009 | |------------+---------------------------------------+--------------| | 12.4XA | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XB | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XC | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XD | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XE | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XF | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XG | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XJ | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XK | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XL | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XM | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XN | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XP | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XQ | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XR | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XT | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XV | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XW | Not Vulnerable | | |------------+---------------------------------------+--------------| | 12.4XY | Not Vulnerable | | |------------+---------------------------------------+--------------| | | | 12.4(20)T4 | | | | | | | | 12.4(22)T3 | | 12.4XZ | Vulnerable; first fixed in 12.4T | | | | | 12.4(24)T2; | | | | Available on | | | | 23-OCT-2009 | |------------+---------------------------------------+--------------| | | | 12.4(22)T3 | | | | | | 12.4YA | Vulnerable; first fixed in 12.4T | 12.4(24)T2; | | | | Available on | | | | 23-OCT-2009 | |------------+---------------------------------------+--------------| | 12.4YB | 12.4(22)YB4 | 12.4(22)YB4 | |------------+---------------------------------------+--------------| | 12.4YD | 12.4(22)YD1 | 12.4(22)YD1 | |------------+---------------------------------------+--------------| | 12.4YE | 12.4(22)YE1 | 12.4(22)YE1 | |------------+---------------------------------------+--------------| | 12.4YG | Not Vulnerable | | +-------------------------------------------------------------------+ Note: No Cisco IOS-XE or Cisco IOS Software Modularity releases are affected by this vulnerability. Workarounds =========== There are no workarounds for this vulnerability other than disabling the Object Groups for ACLs feature. 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-acl.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----- iD8DBQFKukF586n/Gc8U/uARAuXEAJ99dU6Wi1fZMY1yNgedSCx4/+0p8wCeOSKF HmMwzq017QkqDzBFo/JH6DQ= =XJAG -----END PGP SIGNATURE-----