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".
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| The systemd Project | systemd | v242-rc4 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | systemd | 241-3 | — |
| Debian 13 | systemd | 241-3 | — |
| Debian 12 | systemd | 241-3 | — |
| Debian 9 | systemd | 232-25+deb9u11 | DSA-4428-1 |
| Debian 8 | systemd | 215-17+deb8u12 | DLA-1762-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | systemd | 237-3ubuntu10.19 | USN-3938-1 |
| Ubuntu 16.04 LTS | systemd | 229-4ubuntu21.21 | USN-3938-1 |
| Ubuntu 14.04 LTS | systemd | 204-5ubuntu20.31 | USN-3938-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | systemd +7 | 239-45.el8 | RHSA-2021:1611 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.2 EUS | systemd +7 | 239-31.el8_2.7 | RHSA-2021:3900 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | systemd | 239-45.el8 | RLSA-2021:1611 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP1 | systemd | 234-24.30.1 | SUSE-SU-2019:1364-2 |
| SLES 15 | systemd | 234-24.30.1 | SUSE-SU-2019:1364-1 |
| SLES 12 SP4 | systemd | 228-150.66.4 | SUSE-SU-2019:1265-1 |
| SLES 12 SP3 | systemd | 228-150.66.4 | SUSE-SU-2019:1265-1 |
| SLES 12 SP2 | systemd | 228-150.66.4 | SUSE-SU-2019:1265-1 |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP4 | systemd | 228-150.66.4 | SUSE-SU-2019:1265-1 |
| SLES for SAP 12 SP3 | systemd | 228-150.66.4 | SUSE-SU-2019:1265-1 |
| SLES for SAP 12 SP2 | systemd | 228-150.66.4 | SUSE-SU-2019:1265-1 |
| SUSE OpenStack Cloud 7 | systemd | 228-150.66.4 | SUSE-SU-2019:1265-1 |
| SUSE Enterprise Storage 4 | systemd | 228-150.66.4 | SUSE-SU-2019:1265-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | systemd | 249.4-2.2 | openSUSE-SU-2024:11420-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | systemd +9 | 219-78.amzn2.0.20 | ALAS2-2022-1854 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | systemd +7 | 239-45.0.1.el8 | ELSA-2021-1611 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 1
- systemd - Lack of Seat Verification in PAM Module Permits Spoofing Active Session to polkit EDB-46743 · dos · Apr 23, 2019 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 13
- WID-SEC-2025-0227 IBM QRadar SIEM: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 11, 2026
- USN-3938-1 systemd vulnerability Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4428-1 systemd - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1762-1 systemd - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2021:1611 Moderate: systemd security, bug fix, and enhancement update Rocky Linux Security Advisories · Feb 4, 2026
- SUSE-SU-2019:1364-1 Security update for systemd SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:1265-1 Security update for systemd SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11420-1 libsystemd0-249.4-2.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:1364-2 Security update for systemd SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2021:3900 Red Hat Security Advisory: systemd security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:1611 Red Hat Security Advisory: systemd security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- ALAS2-2022-1854 Important: systemd security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Oct 10, 2022
- ELSA-2021-1611 Moderate: systemd security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 25, 2021
References
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3842
- FEDORA-2019-3fa5db9e19 vendor-advisory
- 46743 exploit
- http://packetstormsecurity.com/files/152610/systemd-Seat-Verification-Active-Session-Spoofing.html
- [debian-lts-announce] 20190424 [SECURITY] [DLA 1762-1] systemd security update mailing-list
- openSUSE-SU-2019:1450 vendor-advisory
- [bookkeeper-issues] 20210628 [GitHub] [bookkeeper] padma81 opened a new issue #2746: Security Vulnerabilities in CentOS 7 image, Upgrade image to CentOS 8 mailing-list
- [bookkeeper-issues] 20210629 [GitHub] [bookkeeper] padma81 opened a new issue #2746: Security Vulnerabilities in CentOS 7 image, Upgrade image to CentOS 8 mailing-list