A hidden field manipulation vulnerability was identified in Issuetrak version 17.1 that could be triggered by an authenticated user. When an authenticated user submits a ticket, the request can be intercepted and subsequently modified by using a proxy. The ticket requester can be changed from the original requester to another user in the same application, which the application then accepts.
Solution:
The web application does not sufficiently verify inputs that are assumed to be immutable but are actually externally controllable, such as hidden form fields.