The ISAPI Filter plug-in in Websense Enterprise, Websense Web Security, and Websense Web Filter 6.3.3 and earlier, when used in conjunction with a Microsoft ISA or Microsoft Forefront TMG server, allows remote attackers to bypass intended filtering and monitoring activities for web traffic via an HTTP Via header.
Weaknesses in this category are related to the management of permissions, privileges, and other security features that are used to perform access control.