CVE-2021-20315
Publication date 18 February 2022
Last updated 1 August 2025
Ubuntu priority
Description
A locking protection bypass flaw was found in some versions of gnome-shell as shipped within CentOS Stream 8, when the "Application menu" or "Window list" GNOME extensions are enabled. This flaw allows a physical attacker who has access to a locked system to kill existing applications and start new ones as the locked user, even if the session is still locked.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| gnome-shell | ||
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial |
Not affected
|
|
| 14.04 LTS trusty | Not in release |
Notes
alexmurray
This issue was specific to Centos 8 Stream, in particular as a result of the backport done in https://bugzilla.redhat.com/show_bug.cgi?id=1651378 so does not affect gnome-shell as packaged in Ubuntu
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
6.1 · Medium
|
| Attack vector | Physical |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | High |
| Availability impact | High |
| Vector | CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H |