CVE-2020-28049

Name: CVE-2020-28049
Creator: NVD / NIST
Published: 2020-11-04T19:15:12.137+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.3/10EPSS 0.41%

Last modified Jun 17, 2026

CVE-2020-28049 is a medium-severity vulnerability rated 6.3/10 on the CVSS scale. 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. EPSS estimates a 0.41% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.3/10

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

EPSS Probability

0.41%

33.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Sddm Project	Sddm	< 0.19.0
Opensuse	Leap	15.1
Opensuse	Leap	15.2
Debian	Debian Linux	9.0
Debian	Debian Linux	10.0
Fedoraproject	Fedora	33

References

http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00031.htmlMailing List, Third Party Advisory
https://bugzilla.suse.com/show_bug.cgi?id=CVE-2020-28049Exploit, Issue Tracking, Third Party Advisory
https://github.com/sddm/sddm/blob/v0.19.0/ChangeLogRelease Notes, Third Party Advisory
https://github.com/sddm/sddm/releasesRelease Notes, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/11/msg00009.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GT3EX5NSQJJAKY63ENSMEDX6NYZLYY3S/
https://security.gentoo.org/glsa/202402-02
https://www.debian.org/security/2020/dsa-4783Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00031.htmlMailing List, Third Party Advisory
https://bugzilla.suse.com/show_bug.cgi?id=CVE-2020-28049Exploit, Issue Tracking, Third Party Advisory
https://github.com/sddm/sddm/blob/v0.19.0/ChangeLogRelease Notes, Third Party Advisory
https://github.com/sddm/sddm/releasesRelease Notes, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/11/msg00009.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GT3EX5NSQJJAKY63ENSMEDX6NYZLYY3S/
https://security.gentoo.org/glsa/202402-02
https://www.debian.org/security/2020/dsa-4783Third Party Advisory

Timeline

Published: Nov 4, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-28049?

How severe is CVE-2020-28049?

CVE-2020-28049 has a CVSS score of 6.3/10 (MEDIUM severity). The EPSS model estimates a 0.41% probability of exploitation in the next 30 days.

How do I fix CVE-2020-28049?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-28049?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST