Multiple IOS IPS Vulnerabilities

The Intrusion Prevention System (IPS) feature set of Cisco IOS® contains several vulnerabilities. These include:

Fragmented IP packets may be used to evade signature inspection.

IPS signatures utilizing the regular expression feature of the ATOMIC.TCP signature engine may cause a router to crash resulting in a denial of service.

There are mitigations and workarounds for these vulnerabilities. Cisco has made free software available to address these vulnerabilities for affected customers.

This advisory is posted at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20070213-iosips [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20070213-iosips”].