CVE-2021-4120

Name	CVE-2021-4120
Description	snapd 2.54.2 fails to perform sufficient validation of snap content interface and layout paths, resulting in the ability for snaps to inject arbitrary AppArmor policy rules via malformed content interface and layout declarations and hence escape strict snap confinement. Fixed in snapd versions 2.54.3+18.04, 2.54.3+20.04 and 2.54.3+21.10.1
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)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
snapd (PTS)	buster	2.37.4-1+deb10u1	vulnerable
	buster (security)	2.37.4-1+deb10u2	vulnerable
	bullseye (security), bullseye	2.49-1+deb11u2	fixed
	bookworm	2.57.6-1	fixed
	sid	2.59.5-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
snapd	source	bullseye	2.49-1+deb11u1
snapd	source	(unstable)	2.54.3-1

Notes

[buster] - snapd <ignored> (Minor issue, intrusive backport)
https://bugs.launchpad.net/snapd/+bug/1949368
https://www.openwall.com/lists/oss-security/2022/02/18/2