CVE-2019-3842

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".

Affected

The systemd Project · systemd

CVSS v3.1 NVD

7.0 HIGHCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v3.0 REDHAT

4.5 MEDIUMCVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L

CVSS v2.0 NVD

4.4 MEDIUMAV:L/AC:M/Au:N/C:P/I:P/A:P

EPSS

1.21% chance of exploitation in the next 30 days, 68th percentile

Published

2019-04-09

Updated

2025-06-09

Proof-of-concept exploits (1)

• http://packetstormsecurity.com/files/152610/systemd-Seat-Verification-Active-Session-Spoo…

ExploitDB entries (1)

• https://www.exploit-db.com/exploits/46743

Security advisories

• http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00062.html
• https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3842
• https://lists.debian.org/debian-lts-announce/2019/04/msg00022.html

References

• CVE Record
• NVD entry