CVE-2019-3842

Name: CVE-2019-3842
Creator: NVD / NIST
Published: 2019-04-09T21:29:03.443+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7/10EPSS 1.22%

Last modified Jun 17, 2026

CVE-2019-3842 is a high-severity vulnerability rated 7/10 on the CVSS scale. 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".. EPSS estimates a 1.22% chance of exploitation in the next 30 days.

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".

Metrics

CVSS 3.1

7/10

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

EPSS Probability

1.22%

64.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions	Update
Systemd Project	Systemd	<= 241	—
Systemd Project	Systemd	242	Rc1
Redhat	Enterprise Linux	7.0	—
Fedoraproject	Fedora	30	—
Debian	Debian Linux	8.0	—

References

http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00062.htmlThird Party Advisory
http://packetstormsecurity.com/files/152610/systemd-Seat-Verification-Active-Session-Spoofing.htmlExploit, Third Party Advisory, VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3842Issue Tracking, Third Party Advisory
https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
https://lists.debian.org/debian-lts-announce/2019/04/msg00022.htmlThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/STR36RJE4ZZIORMDXRERVBHMPRNRTHAC/
https://www.exploit-db.com/exploits/46743/Exploit, Third Party Advisory, VDB Entry
http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00062.htmlThird Party Advisory
http://packetstormsecurity.com/files/152610/systemd-Seat-Verification-Active-Session-Spoofing.htmlExploit, Third Party Advisory, VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3842Issue Tracking, Third Party Advisory
https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
https://lists.debian.org/debian-lts-announce/2019/04/msg00022.htmlThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/STR36RJE4ZZIORMDXRERVBHMPRNRTHAC/
https://www.exploit-db.com/exploits/46743/Exploit, Third Party Advisory, VDB Entry

Timeline

Published: Apr 9, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-3842?

How severe is CVE-2019-3842?

CVE-2019-3842 has a CVSS score of 7/10 (HIGH severity). The EPSS model estimates a 1.22% probability of exploitation in the next 30 days.

How do I fix CVE-2019-3842?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-3842?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST