CVE-2021-46837

Name	CVE-2021-46837
Description	res_pjsip_t38 in Sangoma Asterisk 16.x before 16.16.2, 17.x before 17.9.3, and 18.x before 18.2.2, and Certified Asterisk before 16.8-cert7, allows an attacker to trigger a crash by sending an m=image line and zero port in a response to a T.38 re-invite initiated by Asterisk. This is a re-occurrence of the CVE-2019-15297 symptoms but not for exactly the same reason. The crash occurs because there is an append operation relative to the active topology, but this should instead be a replace operation.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub advisories/code/issues, web search, more)
References	DLA-3194-1, DSA-5285-1
Debian Bugs	1018073

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
asterisk (PTS)	buster	1:16.2.1~dfsg-1+deb10u2	vulnerable
	buster (security)	1:16.28.0~dfsg-0+deb10u2	fixed
	bullseye	1:16.28.0~dfsg-0+deb11u1	fixed
	bullseye (security)	1:16.28.0~dfsg-0+deb11u2	fixed
	sid	1:20.1.0~dfsg+~cs6.12.40431414-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Origin	Debian Bugs
asterisk	source	buster	1:16.28.0~dfsg-0+deb10u1	DLA-3194-1
asterisk	source	bullseye	1:16.28.0~dfsg-0+deb11u1	DSA-5285-1
asterisk	source	(unstable)	1:18.9.0~dfsg+~cs6.10.40431411-1		1018073

https://downloads.asterisk.org/pub/security/AST-2021-006.html
This is related to CVE-2019-15297 symptoms but not for exactly the same reason.