Cisco IOS Software Session Initiation Protocol Denial of Service Vulnerabilities

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 https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20110928-sip[“[[Publication_URL]]”].

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:

http://www.cisco.com/web/about/security/intelligence/Cisco_ERP_sep11.html[“http://www.cisco.com/web/about/security/intelligence/Cisco_ERP_sep11.html”]

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:

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20110928-cucm[“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20110928-cucm”]

[“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20110928-cucm”]