CVE-2021-3982
Publication date 29 April 2022
Last updated 26 August 2025
Ubuntu priority
Description
Linux distributions using CAP_SYS_NICE for gnome-shell may be exposed to a privilege escalation issue. An attacker, with low privilege permissions, may take advantage of the way CAP_SYS_NICE is currently implemented and eventually load code to increase its process scheduler priority leading to possible DoS of other services running in the same machine.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| gnome-shell | 25.10 questing |
Not affected
|
| 25.04 plucky |
Not affected
|
|
| 24.04 LTS noble |
Not affected
|
|
| 22.04 LTS jammy |
Not affected
|
|
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial |
Vulnerable
|
|
| 14.04 LTS trusty | Ignored end of standard support |
Notes
mdeslaur
Red Hat's gnome-shell packaging was setting CAP_SYS_NICE on the gnome-shell binary. Ubuntu packaging does not do that, so is not vulnerable to this issue.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
5.5 · Medium
|
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | Low |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | None |
| Availability impact | High |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |