CVE-2021-3997
Publication date 10 January 2022
Last updated 25 August 2025
Ubuntu priority
Description
A flaw was found in systemd. An uncontrolled recursion in systemd-tmpfiles may lead to a denial of service at boot time when too many nested directories are created in /tmp.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| systemd | ||
| 20.04 LTS focal |
Fixed 245.4-4ubuntu3.15
|
|
| 18.04 LTS bionic | Ignored end of standard support | |
| 16.04 LTS xenial | Ignored end of ESM support, was ignored [cannot be exploited] | |
| 14.04 LTS trusty | Ignored end of ESM support, was ignored [cannot be exploited] |
Notes
alexmurray
This vulnerability does not appear to be exploitable for systemd versions before v242 (ie before commit e535840) and onwards hence this is not possible to be exploited on Ubuntu 18.04 LTS and earlier.
Severity score breakdown
CVSS version: CVSS v3.0
Base score
5.5 · Medium
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
References
Related Ubuntu Security Notices (USN)
- USN-5226-1
- systemd vulnerability
- 13 January 2022