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, 220.127.116.11, 18.104.22.168, 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.
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