Cisco Security Advisory – A vulnerability exists in the Cisco Firewall Services Module (FWSM) for the Catalyst 6500 Series Switches and Cisco 7600 Series Routers. The vulnerability may cause the FWSM to stop forwarding traffic and may be triggered while processing multiple, crafted ICMP messages.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/80521/cisco-sa-20090819-fwsm.txt
Source: https://packetstormsecurity.com/files/80521/Cisco-Security-Advisory-20090819-fwsm.html