CVE-2021-34813

Name	CVE-2021-34813
Description	Matrix libolm before 3.2.3 allows a malicious Matrix homeserver to crash a client (while it is attempting to retrieve an Olm encrypted room key backup from the homeserver) because olm_pk_decrypt has a stack-based buffer overflow. Remote code execution might be possible for some nonstandard build configurations.
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	989997

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
olm (PTS)	buster	2.2.2+git20170526.0fd768e+dfsg-1	vulnerable
	bullseye	3.2.1~dfsg-7	vulnerable
	bookworm, sid	3.2.13~dfsg-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
olm	source	experimental	3.2.3~dfsg-1
olm	source	(unstable)	3.2.3~dfsg-3			989997

Notes

[bullseye] - olm <no-dsa> (Minor issue)
[buster] - olm <no-dsa> (Minor issue)
https://gitlab.matrix.org/matrix-org/olm/-/commit/ccc0d122ee1b4d5e5ca4ec1432086be17d5f901b
https://gitlab.matrix.org/matrix-org/olm/-/releases/3.2.3
https://matrix.org/blog/2021/06/14/adventures-in-fuzzing-libolm