Secunia Security Advisory – Fedora has issued an update for asterisk. This fixes a weakness, which can be exploited by malicious people to determine valid user names.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/82887/sa37479.txt
Source: https://packetstormsecurity.com/files/82887/Secunia-Security-Advisory-37479.html