Auth bypass in Systemd Project
CVE-2019-3842
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".
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.012 (67.9th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 68th percentile — 67.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000
Affected products
- Systemd Project — versions 242
- The Systemd Project — versions v242-rc4
- Debian Linux — versions 8.0
- Fedoraproject Fedora — versions 30
- Red Hat Enterprise Linux — versions 7.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- www.exploit-db.com/exploits/46743/ (Exploit, VDB Entry, Third Party Advisory, exploit)
- packetstormsecurity.com/files/152610/systemd-Seat-Verification-Active-Session-S… (Exploit, VDB Entry, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2019/04/msg00022.html (mailing-list, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2019-05/msg00062.html (vendor-advisory, Third Party Advisory)
- lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a4508… (mailing-list)
- lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698… (mailing-list)
Frequently asked questions
- What is CVE-2019-3842?
- CVE-2019-3842 is a high-severity vulnerability in Systemd Project, classified under Improper Authorization. CVSS score: 7.0/10. Published 2019-04-09.
- How severe is CVE-2019-3842?
- High severity. CVSS v3 base score is 7.0 out of 10.
- Is CVE-2019-3842 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.