Cisco IOS Software Object-group Access Control List Bypass Vulnerability

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Updated:May 31, 2014
Document ID:1454797852094132

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Cisco Security Advisory

Cisco IOS Software Object-group Access Control List Bypass Vulnerability

Medium
Advisory ID:
cisco-sa-20090923-acl
First Published:
2009 September 23 16:00 GMT
Version 1.1:
Final
Workarounds:
See below
CVE-2009-2862
CVSS Score:
Base 4.3, Temporal 3.6Click Icon to Copy Verbose Score
AV:N/AC:M/Au:N/C:P/I:N/A:N/E:F/RL:OF/RC:C
CVE-2009-2862

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 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 https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20090923-acl.

    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.

    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

    Note: The Cisco Catalyst 6500 Object Groups feature for policy-based ACLs (PBACLs) is not affected by this vulnerability.

    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.

    Note: The Cisco Catalyst 6500 Object Groups feature for policy-based ACLs (PBACLs) is not affected by this vulnerability.

    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:

    This vulnerability has been assigned Common Vulnerabilities and Exposures (CVE) identifier CVE-2009-2862.

Workarounds

  • There are no workarounds for this vulnerability other than disabling the Object Groups for ACLs feature.

Fixed Software

  • 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 Release

    Availability of Repaired Releases

    Affected 12.0-Based Releases

    First Fixed Release

    Recommended Release

    There are no affected 12.0 based releases.

    Affected 12.1-Based Releases

    First Fixed Release

    Recommended Release

    There are no affected 12.1 based releases.

    Affected 12.2-Based Releases

    First Fixed Release

    Recommended Release

    There are no affected 12.2 based releases.

    Affected 12.3-Based Releases

    First Fixed Release

    Recommended Release

    There are no affected 12.3 based releases.

    Affected 12.4-Based Releases

    First Fixed Release

    Recommended Release

    12.4

    Not Vulnerable

    		  

    12.4GC

    Vulnerable; Contact your support 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

    		  

    12.4MD

    12.4(22)MD1

    12.4(11)MD9

    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

    		  

    12.4T

    12.4(22)T2

    12.4(20)T4

    12.4(24)T1

    12.4(20)T4

    12.4(22)T3

    12.4(24)T2; 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

    		  

    12.4XZ

    Vulnerable; first fixed in 12.4T

    12.4(20)T4

    12.4(22)T3

    12.4(24)T2; Available on 23-OCT-2009

    12.4YA

    Vulnerable; first fixed in 12.4T

    12.4(22)T3

    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.

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.

Cisco Security Vulnerability Policy

  • To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.

Subscribe to Cisco Security Notifications

Related to This Advisory

URL

Revision History

  • Revision 1.0

    2009-September-23

    Initial public release

    Show Less

Cisco Security Vulnerability Policy

  • To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.

Subscribe to Cisco Security Notifications

Related to This Advisory