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CVE-2019-3842VulnerabilityPublished Updated

CVE-2019-3842: systemd · CWE-285

Affects systemdSource CVE Database V5

0

Not known to be exploited · public exploit available (Exploit-DB) · CVSS 4.5 Medium : upgrade to 242-rc4 as a priority.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.0 base score
4.5Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
1.2% chance of exploitation in 30 days – higher than 68% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 242-rc4
CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

  1. Disclosed: evidence found.

    CVE published 9 Apr 2019

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  4. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

Timeline

  1. CVE ID reserved

    by redhat

    , 96 days before disclosure

  2. CVE published

    on cve.org

    , t = 0

  3. First Exploit-DB entry (opens in a new tab)

    systemd - Lack of Seat Verification in PAM Module Permits Spoofing Active Session to polkit

    , 14 days after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

What to do

Upgrade systemd to 242-rc4.

Affected software

ProductAffectedFixed in
Red Hatsystemdpkg:rpm/systemdOther threatsAffected
  • <242-rc4
Fixed in
  • 242-rc4

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2019-3842, European organizations should: 1) Upgrade systemd to version v242-rc4 or later, where the vulnerability is fixed. 2) Review and harden PAM and polkit configurations to minimize the risk of environment variable manipulation, including restricting which environment variables are passed and sanitized during authentication. 3) Implement strict user privilege separation and limit local user accounts to reduce the attack surface. 4) Monitor system logs for unusual polkit authorization requests or environment variable anomalies that could indicate exploitation attempts. 5) Employ security tools that detect privilege escalation attempts and anomalous behavior related to PAM and polkit. 6) Conduct regular security audits and penetration testing focused on local privilege escalation vectors. These steps go beyond generic advice by focusing on configuration hardening and monitoring specific to the vulnerability's exploitation path.

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".

References

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