CVE-2020-28049

MEDIUM

SDDM < 0.19.0 - Unauthenticated X Server Access via Race Condition

Title source: llm
STIX 2.1

Description

An issue was discovered in SDDM before 0.19.0. It incorrectly starts the X server in a way that - for a short time period - allows local unprivileged users to create a connection to the X server without providing proper authentication. A local attacker can thus access X server display contents and, for example, intercept keystrokes or access the clipboard. This is caused by a race condition during Xauthority file creation.

References (8)

Core 8
Core References
Third Party Advisory vendor-advisory
https://www.debian.org/security/2020/dsa-4783
Mailing List, Third Party Advisory mailing-list
https://lists.debian.org/debian-lts-announce/2020/11/msg00009.html
Mailing List, Third Party Advisory vendor-advisory
http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00031.html
Third Party Advisory vendor-advisory
https://security.gentoo.org/glsa/202402-02
Exploit, Issue Tracking, Third Party Advisory
https://bugzilla.suse.com/show_bug.cgi?id=CVE-2020-28049
Release Notes, Third Party Advisory
https://github.com/sddm/sddm/releases

Scores

CVSS v3 6.3
EPSS 0.0004
EPSS Percentile 11.3%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-362
Status published
Products (6)
debian/debian_linux 9.0
debian/debian_linux 10.0
fedoraproject/fedora 33
opensuse/leap 15.1
opensuse/leap 15.2
sddm_project/sddm < 0.19.0
Published Nov 04, 2020
Tracked Since Feb 18, 2026