CVE-2007-4103: Digium Asterisk

High severity, CVSS 7.5. EPSS: 5.9% chance of exploitation in the next 30 days.

The IAX2 channel driver (chan_iax2) in Asterisk Open 1.2.x before 1.2.23, 1.4.x before 1.4.9, and Asterisk Appliance Developer Kit before 0.6.0, when configured to allow unauthenticated calls, allows remote attackers to cause a denial of service (resource exhaustion) via a flood of calls that do not complete a 3-way handshake, which causes an ast_channel to be allocated but not released.

Affected products

• Digium Asterisk: from 1.2.20, before 1.2.23 (fixed in 1.2.23); from 1.4.0, before 1.4.9 (fixed in 1.4.9)
• Digium Asterisk Appliance Developer Kit: before 0.6.0 (fixed in 0.6.0)

Published 2007-07-31. Last modified 2026-06-16.