An issue was discovered in Asterisk Open Source through 13.27.0, 14.x and
15.x through 15.7.2, and 16.x through 16.4.0, and Certified Asterisk
through 13.21-cert3. A pointer dereference in chan_sip while handling SDP
negotiation allows an attacker to crash Asterisk when handling an SDP
answer to an outgoing T.38 re-invite. To exploit this vulnerability an
attacker must cause the chan_sip module to send a T.38 re-invite request to
them. Upon receipt, the attacker must send an SDP answer containing both a
T.38 UDPTL stream and another media stream containing only a codec (which
is not permitted according to the chan_sip configuration).
Upstream:released (1:16.2.1~dfsg-2)
Ubuntu 12.04 ESM (Precise Pangolin):DNE
Ubuntu 14.04 ESM (Trusty Tahr):DNE
Ubuntu 16.04 LTS (Xenial Xerus):needed
Ubuntu 18.04 LTS (Bionic Beaver):needed
Ubuntu 19.10 (Eoan Ermine):not-affected (1:16.2.1~dfsg-2build2)
Ubuntu 20.04 (Focal Fossa):not-affected (1:16.2.1~dfsg-2build2)
More Information

Updated: 2020-04-24 03:53:13 UTC (commit d3f8a6ed481830fb100109a132bef581fc4176fe)