Asterisk contains a flaw that may allow an attacker to determine valid usernames. The issue is triggered when different responses are being sent using a valid or an invalid username in 'REGISTER' messages. This can be exploited to determine valid usernames by sending a specially crafted 'REGISTER' message. .
Remote / Network Access
Loss of Confidentiality
Patch / RCS,
Upgrade to version 1.2.35, 126.96.36.199, 188.8.131.52, 1.6.19 or higher, as it has been reported to fix this vulnerability. In addition, Digium has released a patch for some older versions.
The database information may change without any notice. Use of the information constitutes acceptance for use in an AS IS condition, and there are NO
warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall the copyright
holder or distributor (OSVDB or OSF) be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.