CVE-2021-23240

Name	CVE-2021-23240
Description	selinux_edit_copy_tfiles in sudoedit in Sudo before 1.9.5 allows a local unprivileged user to gain file ownership and escalate privileges by replacing a temporary file with a symlink to an arbitrary file target. This affects SELinux RBAC support in permissive mode. Machines without SELinux are not vulnerable.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, 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
sudo (PTS)	bullseye	1.9.5p2-3+deb11u1	fixed
	bullseye (security)	1.9.5p2-3+deb11u2	fixed
	bookworm, bookworm (security)	1.9.13p3-1+deb12u2	fixed
	trixie	1.9.16p2-3	fixed
	forky, sid	1.9.17p2-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
sudo	source	(unstable)	1.9.5-1	unimportant

Notes

https://www.openwall.com/lists/oss-security/2021/01/11/2
https://www.sudo.ws/repos/sudo/rev/8fcb36ef422a
https://www.sudo.ws/alerts/sudoedit_selinux.html
Neutralised by kernel hardening (fs.protected_symlinks = 1)