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".
CVE-2019-3842
Score 7.0 from GitHub Security Advisory (severity: HIGH) published 2022-05-13. NVD baseline CVSS 7.0; sources differ by 0.0.
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.0
- EG Score
- 7.0(medium)
- EG Risk
- 57(Track)EG Risk 57/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity70% × 45%Exploitation65% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 65.4%
- KEV
- Not listed
Published
April 9, 2019
Last Modified
November 21, 2024
References (16)
- secalert@redhathttp://lists.opensuse.org/opensuse-security-announce/2019-05/msg00062.html
- secalert@redhathttp://packetstormsecurity.com/files/152610/systemd-Seat-Verification-Active-Session-Spoofing.html
- secalert@redhathttps://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3842
- secalert@redhathttps://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
- secalert@redhathttps://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
- secalert@redhathttps://lists.debian.org/debian-lts-announce/2019/04/msg00022.html
- secalert@redhathttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/STR36RJE4ZZIORMDXRERVBHMPRNRTHAC/
- secalert@redhathttps://www.exploit-db.com/exploits/46743/
- af854a3a-2127-422b-91ae-364da2661108http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00062.html
- af854a3a-2127-422b-91ae-364da2661108http://packetstormsecurity.com/files/152610/systemd-Seat-Verification-Active-Session-Spoofing.html
- af854a3a-2127-422b-91ae-364da2661108https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3842
- af854a3a-2127-422b-91ae-364da2661108https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
- af854a3a-2127-422b-91ae-364da2661108https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
- af854a3a-2127-422b-91ae-364da2661108https://lists.debian.org/debian-lts-announce/2019/04/msg00022.html
- af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/STR36RJE4ZZIORMDXRERVBHMPRNRTHAC/
Patch Availability(3)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | udev-udeb (237-3ubuntu10.19) @ bionic | 2026-05-27 | ubuntu |
| redhat | systemd-0:239-31.el8_2.7 | 2021-10-19 | redhat |
| redhat | systemd-0:239-45.el8 | 2021-05-18 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
All Vendor Advisories
(4)
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
- Microsoft MSRCCVE-2019-38422020-08-18
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".
- Red HatRHSA-2021:1611MODERATE2019-04-08
RHSA-2021:1611 — Moderate
- Red HatRHSA-2021:3900MODERATE2019-04-08
RHSA-2021:3900 — Moderate
- UbuntuUSN-3938-1MEDIUM
systemd vulnerability
Data Freshness Timeline
(refreshed 14× in last 7d / 46× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-23 01:45 UTCEG score recompute
- 2026-07-22 22:25 UTCEG score recompute
- 2026-07-22 14:05 UTCEPSS rescore
- 2026-07-21 15:22 UTCEPSS rescore
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- 2026-07-20 18:32 UTCOSV refresh
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- 2026-07-03 13:56 UTCOSV refresh
- 2026-07-01 15:03 UTCEPSS rescore
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- 2026-06-15 03:43 UTCOSV refresh
- 2026-06-14 23:15 UTCEPSS rescore
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- 2026-05-27 20:42 UTCEG score recompute
- 2026-05-27 20:42 UTCVendor advisory
- 2026-05-27 20:42 UTCGHSA enrichment
- 2026-05-27 13:39 UTCEPSS rescore
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Publicly available exploits
(1 reference)Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
- Exploit-DBEDB-46743✓ verifiedFirst seen Apr 23, 2019
systemd - Lack of Seat Verification in PAM Module Permits Spoofing Active Session to polkit
Open source ↗
Frequently asked(5)
What is CVE-2019-3842?
When was CVE-2019-3842 disclosed?
Is CVE-2019-3842 actively exploited?
What is the CVSS score of CVE-2019-3842?
How do I remediate CVE-2019-3842?
Dependency Blast Radius
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