Symantec Scan Engine 5.0.0.24, and possibly other versions before 5.1.0.7, uses a client-side check to verify a password, which allows remote attackers to gain administrator privileges via a modified client that sends certain XML requests.
https://exchange.xforce.ibmcloud.com/vulnerabilities/25972
http://www.vupen.com/english/advisories/2006/1464
http://www.symantec.com/avcenter/security/Content/2006.04.21.html
http://www.securityfocus.com/bid/17637
http://www.securityfocus.com/archive/1/431734/100/0/threaded
http://www.securityfocus.com/archive/1/431724/100/0/threaded