Improper authorization in systemd
Priority LOW 33CWE-285Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 2 fixed, 1 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-285.
Summary
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".
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01207 68th percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by the CNA and NVD
Fix Partial Red Hat: 2 advisoriesRed Hat: 2 fixed, 1 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| systemd | systemd | v242-rc4 | — | No fix listed | CNA |
- systemd Vendorsystemd Affected v242-rc4 Fixed in — No fix listed CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:* | up to 241 | Vulnerable | systemd |
| cpe:2.3:a:systemd_project:systemd:242:rc1:*:*:*:*:*:* | 242 rc1 | Vulnerable | systemd |
| cpe:2.3:a:systemd_project:systemd:242:rc2:*:*:*:*:*:* | 242 rc2 | Vulnerable | systemd |
| cpe:2.3:a:systemd_project:systemd:242:rc3:*:*:*:*:*:* | 242 rc3 | Vulnerable | systemd |
| cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
| cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:* | 30 | Vulnerable | Fedoraproject |
| cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Debian |
- cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:* Versions up to 241 Vulnerable ·systemd
- cpe:2.3:a:systemd_project:systemd:242:rc1:*:*:*:*:*:* Versions 242 rc1 Vulnerable ·systemd
- cpe:2.3:a:systemd_project:systemd:242:rc2:*:*:*:*:*:* Versions 242 rc2 Vulnerable ·systemd
- cpe:2.3:a:systemd_project:systemd:242:rc3:*:*:*:*:*:* Versions 242 rc3 Vulnerable ·systemd
- cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
- cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:* Versions 30 Vulnerable ·Fedoraproject
- cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Debian
Remediation
Red Hat 2 advisories
- RHSA-2021:3900 Released 2021-10-19 · Red Hat rating Moderatesystemd security update
- Red Hat Enterprise Linux BaseOS EUS (v. 8.2) systemd-239-31.el8_2.7, systemd-container-239-31.el8_2.7, systemd-devel-239-31.el8_2.7 +5
- RHSA-2021:1611 Released 2021-05-18 · Red Hat rating Moderatesystemd security, bug fix, and enhancement update
- Red Hat Enterprise Linux BaseOS (v. 8) systemd-239-45.el8, systemd-container-239-45.el8, systemd-devel-239-45.el8 +5
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2021:1611 |
| Red Hat Enterprise Linux BaseOS EUS (v. 8.2) | Fixed | RHSA-2021:3900 |
Timeline
- 2026-10-02 Threatist record created from CVE-2019-3842
- 2026-10-03 Alias added: GHSA-c23j-qp89-q76c
References
Exploit 2
Advisory 4
Other 2
- [bookkeeper-issues] 20210628 [GitHub] [bookkeeper] padma81 opened a new issue #2746: Security Vulnerabilities in CentOS 7 image, Upgrade image to CentOS 8
- [bookkeeper-issues] 20210629 [GitHub] [bookkeeper] padma81 opened a new issue #2746: Security Vulnerabilities in CentOS 7 image, Upgrade image to CentOS 8
More Systemd vulnerabilities
- TI-2023-11736 systemd before 247 does not adequately block local privilege escalation for some Sudo… CVSS 3.1HIGH 7.8
- TI-2017-06857 In systemd through 233, certain sizes passed to dns_packet_new in systemd-resolved can… CVSS 3.1HIGH 7.5
- TI-2026-29031 In nspawn in systemd 233 through 259 before 260, an escape-to-host action can occur via a crafted optional config file. CVSS 3.1MEDIUM 6.4
- TI-2022-04038 Information disclosure in systemd CVSS 3.1MEDIUM 5.5
- TI-2025-04111 Systemd-coredump: race condition that allows a local attacker to crash a suid program and… CVSS 3.1MEDIUM 4.7
- TI-2017-11647 In systemd 223 through 235, a remote DNS server can respond with a custom crafted DNS… CVSS 3.1HIGH 7.5
Sources
- CVE-2019-3842 · CVE Program
- CVE-2019-3842 · NVD
- FIRST EPSS
- GHSA-c23j-qp89-q76c · GitHub Advisory Database · CC BY 4.0
- CVE-2019-3842 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences