CVE-2021-26713

Name	CVE-2021-26713
Description	A stack-based buffer overflow in res_rtp_asterisk.c in Sangoma Asterisk before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1 and Certified Asterisk before 16.8-cert6 allows an authenticated WebRTC client to cause an Asterisk crash by sending multiple hold/unhold requests in quick succession. This is caused by a signedness comparison mismatch.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

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+deb10u4	fixed
	bullseye	1:16.28.0~dfsg-0+deb11u3	fixed
	bullseye (security)	1:16.28.0~dfsg-0+deb11u4	fixed
	sid	1:20.6.0~dfsg+~cs6.13.40431414-2	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
asterisk	source	(unstable)	(not affected)

- asterisk <not-affected> (Only affects 16.16.0 onwards)
https://downloads.asterisk.org/pub/security/AST-2021-004.html