CVE-2008-1897

The IAX2 channel driver (chan_iax2) in Asterisk Open Source 1.0.x, 1.2.x
before 1.2.28, and 1.4.x before 1.4.19.1; Business Edition A.x.x, B.x.x
before B.2.5.2, and C.x.x before C.1.8.1; AsteriskNOW before 1.0.3;
Appliance Developer Kit 0.x.x; and s800i before 1.1.0.3, when configured to
allow unauthenticated calls, does not verify that an ACK response contains
a call number matching the server’s reply to a NEW message, which allows
remote attackers to cause a denial of service (traffic amplification) via a
spoofed ACK response that does not complete a 3-way handshake. NOTE: this
issue exists because of an incomplete fix for CVE-2008-1923.

Bugs

• <https://bugs.launchpad.net/ubuntu/+source/asterisk/+bug/220849&gt;