Cisco FWSM 3.x before 3.1(3.2), when authentication is configured to use "aaa authentication match" or "aaa authentication include", allows remote attackers to cause a denial of service (device reboot) via a long HTTP request.
http://www.vupen.com/english/advisories/2007/0609
http://www.securityfocus.com/bid/22561
http://www.cisco.com/en/US/products/products_security_advisory09186a00807e2481.shtml