Cisco IOS Authentication Proxy for HTTP security bypass

ciscoios-authenticationproxy-sec-bypass (53453) The risk level is classified as MediumMedium Risk


Multiple Cisco IOS devices configured with Authentication Proxy for HTTP(S), Web Authentication or the consent feature could allow a remote attacker to bypass security restrictions, caused by a race condition in the code. If a valid session or accepted consent session exists, a remote attacker could bypass the authentication proxy server or the consent Web page to gain unauthorized access to network resources.


Base Score: 7.1
  Access Vector: Network
  Access Complexity: Medium
  Authentication: None
  Confidentiality Impact: Complete
  Integrity Impact: None
  Availability Impact: None
Temporal Score: 5.3
  Exploitability: Unproven
  Remediation Level: Official-Fix
  Report Confidence: Confirmed


Bypass Security


Refer to cisco-sa-20090923-auth-proxy for patch, upgrade or suggested workaround information. See References.


  • cisco-sa-20090923-auth-proxy: Cisco IOS Software Authentication Proxy Vulnerability .
  • BID-36491: Cisco IOS Authentication Proxy for HTTP(S) Authentication Bypass Vulnerability
  • CVE-2009-2863: Race condition in the Firewall Authentication Proxy feature in Cisco IOS 12.0 through 12.4 allows remote attackers to bypass authentication, or bypass the consent web page, via a crafted request, aka Bug ID CSCsy15227.
  • OSVDB ID: 58340: Cisco IOS Firewall Authentication Proxy Server / Consent Page Bypass
  • SA36835: Cisco IOS Multiple Vulnerabilities
  • SECTRACK ID: 1022935: Cisco IOS Authentication Proxy Race Condition Lets Remote Users Bypass Access Controls

Platforms Affected:

  • Cisco IOS


Sep 23, 2009

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