A vulnerability exists 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 an affected device to reload. Affected devices must be configured to process SIP messages and for pass-through of Session Description Protocol (SDP) for this vulnerability to be exploitable.
Cisco has released free software updates that address this vulnerability. There are no workarounds for devices that must run SIP; however, mitigations are available to limit exposure to the vulnerability.
This advisory is available at the following link:
Note: The September 26, 2012, Cisco IOS Software Security Advisory bundled publication includes nine Cisco Security Advisories. Eight of the advisories address vulnerabilities in Cisco IOS Software, and one advisory addresses a vulnerability in Cisco Unified Communications Manager. Each Cisco IOS Software Security 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 Cisco IOS Software vulnerabilities in the September 2012 bundled publication.
Individual publication links are in "Cisco Event Response: Semi-Annual Cisco IOS Software Security Advisory Bundled Publication" at the following link: