Cisco Firewall Services Module ACL security bypass

cisco-fwsm-acl-security-bypass (32521) The risk level is classified as MediumMedium Risk

Description:

Cisco Firewall Services Module (FWSM) could allow a remote attacker to bypass security caused by a corruption error in the Access Control List (ACL). When ACL's that use object groups are manipulated, access control entries (ACEs) in the ACL could be evaluated out of order or not evaluated. An authenticated attacker with administrator privileges could exploit this vulnerability to bypass security restrictions.

Note: NAT (policy NAT and NAT exemption), AAA (auth-proxy), access controls for the device (SSH, Telnet, HTTP, and ICMP) could also be affected by this vulnerability.

*CVSS:

Base Score: 2.4
  Access Vector: Remote
  Access Complexity: High
  Authentication: Required
  Confidentiality Impact: None
  Integrity Impact: Complete
  Availability Impact: None
 
Temporal Score: 1.8
  Exploitability: Unproven
  Remediation Level: Official-Fix
  Report Confidence: Confirmed

Consequences:

Bypass Security

Remedy:

Refer to cisco-sa-20070214-fwsm for patch, upgrade, or suggested workaround information. See References.

References:

  • cisco-sa-20070214-fwsm: Cisco Security Advisory: Multiple Vulnerabilities in Firewall Services Module.
  • BID-22561: Cisco Multiple Products Multiple Remote Denial Of Service Vulnerabilities
  • CVE-2007-0968: Unspecified vulnerability in Cisco Firewall Services Module (FWSM) before 2.3(4.7) and 3.x before 3.1(3.1) causes the access control entries (ACE) in an ACL to be improperly evaluated, which allows remote authenticated users to bypass intended certain ACL protections.
  • OSVDB ID: 33061: Cisco Firewall Services Module (FWSM) ACE Evaluation ACL Bypass
  • SA24172: Cisco Firewall Services Module Multiple Vulnerabilities
  • SECTRACK ID: 1017650: Cisco Firewall Service Module Lets Remote Users Deny Service and Potentially Bypass Intended ACLs

Platforms Affected:

  • Cisco Firewall Services Module 2.3
  • Cisco Firewall Services Module 3.1

Reported:

Feb 14, 2007

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The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall IBM be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.

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