Buffer overflow in Cisco PIX Firewall 5.2.x to 5.2.8, 6.0.x to 6.0.3, 6.1.x to 6.1.3, and 6.2.x to 6.2.1 allows remote attackers to cause a denial of service via HTTP traffic authentication using (1) TACACS+ or (2) RADIUS.
http://www.securityfocus.com/bid/6212
http://www.iss.net/security_center/static/10661.php
http://www.cisco.com/warp/public/707/pix-multiple-vuln-pub.shtml