The web portal interface in Citrix Access Gateway (aka Citrix Advanced Access Control) before Advanced Edition 4.5 HF1 places a session ID in the URL, which allows context-dependent attackers to hijack sessions by reading "residual information", including the a referer log, browser history, or browser cache.
Exposure of Sensitive Information to an Unauthorized Actor The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.