CVE-2011-2666: Digium Asterisk

Medium severity, CVSS 5.0. EPSS: 1.3% chance of exploitation in the next 30 days.

The default configuration of the SIP channel driver in Asterisk Open Source 1.4.x through 1.4.41.2 and 1.6.2.x through 1.6.2.18.2 does not enable the alwaysauthreject option, which allows remote attackers to enumerate account names by making a series of invalid SIP requests and observing the differences in the responses for different usernames, a different vulnerability than CVE-2011-2536.

Affected products

• Digium Asterisk: version 1.6.2.0 only; version 1.6.2.1 only; version 1.6.2.2 only; version 1.6.2.3 only; version 1.6.2.4 only; version 1.6.2.5 only; …

Published 2011-07-06. Last modified 2026-06-16.