CVE-2021-3997

Publication date 10 January 2022

Last updated 24 July 2024


Ubuntu priority

Cvss 3 Severity Score

5.5 · Medium

Score breakdown

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
systemd 21.10 impish
Fixed 248.3-1ubuntu8.2
21.04 hirsute
Fixed 247.3-3ubuntu3.7
20.04 LTS focal
Fixed 245.4-4ubuntu3.15
18.04 LTS bionic Ignored cannot be exploited
16.04 LTS xenial 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

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

References

Related Ubuntu Security Notices (USN)

    • USN-5226-1
    • systemd vulnerability
    • 13 January 2022

Other references