CVE-2019-3842 Information

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 Vector

CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Reference

http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00062.html http://packetstormsecurity.com/files/152610/systemd-Seat-Verification-Active-Session-Spoofing.html https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3842 https://lists.debian.org/debian-lts-announce/2019/04/msg00022.html https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/STR36RJE4ZZIORMDXRERVBHMPRNRTHAC/ https://www.exploit-db.com/exploits/46743/

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

7.0