Debian Security Advisory
DLA-2436-1 sddm -- LTS security update
- Date Reported:
- 06 Nov 2020
- Affected Packages:
- Security database references:
- In Mitre's CVE dictionary: CVE-2020-28049.
- More information:
It was discovered that there was an issue in the sddm display manager where local unprivileged users could create a connection to the X server.
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.
For Debian 9
Stretch, these problems have been fixed in version 0.14.0-4+deb9u2.
We recommend that you upgrade your sddm packages.
Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: https://wiki.debian.org/LTS