CVE-2019-3842

Name	CVE-2019-3842
Description	In systemd before v242-rc4, it was discovered that pam_systemd does not properly sanitize the environment before using the XDG_SEAT variable. It is possible for an attacker, in some particular configurations, to set a XDG_SEAT environment variable which allows for commands to be checked against polkit policies using the "allow_active" element rather than "allow_any".
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-1762-1, DSA-4428-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
systemd (PTS)	bullseye	247.3-7+deb11u5	fixed
	bullseye (security)	247.3-7+deb11u6	fixed
	bookworm	252.31-1~deb12u1	fixed
	sid, trixie	257~rc2-3	fixed

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

Package	Type	Release	Fixed Version	Origin
systemd	source	jessie	215-17+deb8u12	DLA-1762-1
systemd	source	stretch	232-25+deb9u11	DSA-4428-1
systemd	source	(unstable)	241-3

Notes

https://bugs.chromium.org/p/project-zero/issues/detail?id=1756
https://bugs.launchpad.net/bugs/1812316
https://github.com/systemd/systemd/commit/83d4ab55336ff8a0643c6aa627b31e351a24040a