Cisco has acknowledged some vulnerabilities in Cisco Firewall Services Module (FWSM), which can be exploited by malicious people to cause a DoS (Denial of Service).

1) An unspecified error exists within the handling of HTTPS packets. This can be exploited to reboot an affected FWSM by sending specially crafted HTTPS packets.

Successful exploitation requires that the HTTPS server is enabled (disabled by default).

The vulnerability is reported in versions 3.1 and 3.2.

2) An unspecified error exists within the handling of Media Gateway Control Protocol (MGCP) packets. This can be exploited to reboot the FWSM by sending specially crafted MGCP packets.

Successful exploitation requires that the MGCP application layer protocol inspection is enabled (disabled by default).

The vulnerability is reported in version 3.1.

NOTE: An error when loading manipulated ACLs (Access Control Lists) is also reported.

Solution
Update to a fixed version (please see vendor's advisory for details).

Provided and/or discovered by
Reported by the vendor.

Changelog
Further details available to Secunia VIM customers

Original Advisory
http://www.cisco.com/warp/public/707/cisco-sa-20071017-fwsm.shtml

Deep Links
Links available to Secunia VIM customers