Multiple vulnerabilities exist in the Session Initiation Protocol (SIP) implementation in Cisco IOS Software and Cisco IOS XE Software that could allow an unauthenticated, remote attacker to cause a reload of an affected device or trigger memory leaks that may result in system instabilities. Affected devices would need to be configured to process SIP messages for these vulnerabilities to be exploitable.
Cisco has released software updates that address these vulnerabilities. There are no workarounds for devices that must run SIP; however, mitigations are available to limit exposure to the vulnerabilities.
This advisory is posted at http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20110928-sip["%5B%5BPublication_URL%5D%5D"].
Note: The September 28, 2011, Cisco IOS Software Security Advisory bundled publication includes ten Cisco Security Advisories. Nine of the advisories address vulnerabilities in Cisco IOS Software, and one advisory addresses a vulnerability in Cisco Unified Communications Manager. Each advisory lists the Cisco IOS Software releases that correct the vulnerability or vulnerabilities detailed in the advisory as well as the Cisco IOS Software releases that correct all vulnerabilities in the September 2011 Bundled Publication.
Individual publication links are in "Cisco Event Response: Semiannual Cisco IOS Software Security Advisory Bundled Publication" at the following link:
Cisco Unified Communications Manager is affected by one of the vulnerabilities described in this advisory. A separate Cisco Security Advisory has been published to disclose the vulnerability that affects the Cisco Unified Communications Manager at the following location: