CVE-2019-3842: debian debian_linux Improper Authorization
Vulnerability summary
CVE-2019-3842 is a high (CVSS 7.0) Improper Authorization vulnerability in debian debian_linux. EPSS estimates a 1.21% chance of exploitation in the next 30 days, higher than 68.4% of scored vulnerabilities. 2 public exploits are recorded.
Not severe (CVSS 4.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 7 · Related 5Timeline
- 09-04-2019PublishedVulnerability first disclosed.
- 09-06-2025Last modifiedVulnerability information updated.
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".
CVSS metrics
8 scores · 5 sources · 3 versions- OSV · UbuntuEcosystem advisory · calculated7.0HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.0HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · ChainguardEcosystem advisory · calculated7.0HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated7.0HighCVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HDiffers
- NVDNIST4.5MediumCVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
EPSS trend
Probability
1.21%
Chance of exploitation in the next 30 days
Percentile
68%
Versus all other CVEs
30-day change
No change 0.00 pp
From 1.21% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
2 foundExploit Reference (packetstormsecurity.com)
Maturity: unknown
systemd - Lack of Seat Verification in PAM Module Permits Spoofing Active Session to polkit
Maturity: poc
Weaknesses
CWE · root cause- CWE-285Improper AuthorizationThe product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
- CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Chainguard5 products
- py3-systemdAll versions (No fix recorded)
- py3.10-systemdAll versions (No fix recorded)
- py3.11-systemdAll versions (No fix recorded)
- py3.12-systemdAll versions (No fix recorded)
- py3.13-systemdAll versions (No fix recorded)
Debian2 products
- systemd< 241-3 | < 232-25+deb9u11
- debian_linuxEOL8.0
Fedoraproject1 product
- fedoraEOL30
Redhat1 product
- enterprise_linuxEOL7.0
Systemd_project1 product
- systemd≤ 241 | 242:rc1 | 242:rc2 | 242:rc3
The systemd project1 product
- systemdv242-rc4
Ubuntu1 product
- systemd< 204-5ubuntu20.31 | < 229-4ubuntu21.21 | < 237-3ubuntu10.19
7 vendors · 12 products
References
13 links- bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3842X Refsource CONFIRMREPORTIssue TrackingThird Party Advisory
- www.exploit-db.com/exploits/46743/ExploitX Refsource EXPLOIT DBEVIDENCEThird Party AdvisoryVDB Entry
- packetstormsecurity.com/files/152610/systemd-Seat-Verification-Active-Session-Spoofing.htmlX Refsource MISCEVIDENCEExploitThird Party AdvisoryVDB Entry
lists.debian.org/debian-lts-announce/2019/04/msg00022.htmlMailing ListX Refsource MLISTAdvisoryThird Party Advisory- lists.opensuse.org/opensuse-security-announce/2019-05/msg00062.htmlVendor AdvisoryX Refsource SUSEAdvisoryThird Party Advisory
