CVE-2021-26717

Name	CVE-2021-26717
Description	An issue was discovered in Sangoma Asterisk 16.x before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1 and Certified Asterisk before 16.8-cert6. When re-negotiating for T.38, if the initial remote response was delayed just enough, Asterisk would send both audio and T.38 in the SDP. If this happened, and the remote responded with a declined T.38 stream, then Asterisk would crash.
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)
Debian Bugs	983157

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	fixed
	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	Debian Bugs
asterisk	source	stretch	(not affected)
asterisk	source	buster	(not affected)
asterisk	source	(unstable)	1:16.16.1~dfsg-1	983157

Notes

[buster] - asterisk <not-affected> (Introduced in 16.15.0)
[stretch] - asterisk <not-affected> (Introduced in 16.15.0)
https://downloads.asterisk.org/pub/security/AST-2021-002.html