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Cisco Firewall Services Module vulnerable to DoS via inspection of malformed SIP messages

Vulnerability Note VU#430969

Original Release Date: 2007-02-16 | Last Revised: 2007-02-22


Cisco Firewall Services Module fails to properly inspect SIP messages. This vulnerability may allow a remote attacker to cause a denial of service condition.


The Cisco Firewall Services Module is an integrated firewall service for Cisco Catalyst 6500 series switches and Cisco 7600 series routers. This module fails to properly inspect SIP messages which may cause the system to crash. This vulnerability can be exploited when an attacker sends a specially crafted SIP message to the system.

Cisco states that SIP inspection is enabled by default in 2.x versions of the module.


A remote, unauthenticated attacker may be able to cause the system to crash.



Cisco states this issue has been addressed in 2.3(4.12) for the 2.3.x series, and 3.1(3.24) for the 3.x series. Please see Cisco Security Advisory cisco-sa-20070214-fwsm for further information.


Disable deep packet inspection. Please see Cisco Security Advisory cisco-sa-20070214-fwsm for further information.

Vendor Information

Affected   Unknown   Unaffected

Cisco Systems, Inc.

Updated:  February 16, 2007



Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.


Please see Cisco Security Advisory cisco-sa-20070214-fwsm for futher details.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

CVSS Metrics

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A



Thanks to Cisco Systems Product Security Incident Response Team for reporting this vulnerability.

This document was written by Katie Steiner.

Other Information

CVE IDs: CVE-2007-0961
Severity Metric: 12.60
Date Public: 2007-02-14
Date First Published: 2007-02-16
Date Last Updated: 2007-02-22 14:15 UTC
Document Revision: 9

Sponsored by the Department of Homeland Security Office of Cybersecurity and Communications.