Secunia Security Advisory – Davide Del Vecchio has reported a weakness in Remedy Action Request System, which can be exploited by malicious people to identify valid user accounts.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/53713/sa23775.txt
Source: https://packetstormsecurity.com/files/53713/Secunia-Security-Advisory-23775.html