CVE-2021-3996

Publication date 1 February 2022

Last updated 24 July 2024

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

5.5 · Medium

Score breakdown

A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows a local user on a vulnerable system to unmount other users’ filesystems that are either world-writable themselves (like /tmp) or mounted in a world-writable directory. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems.

Read the notes from the security team

Status

Package Ubuntu Release Status
util-linux 22.04 LTS jammy
Fixed 2.37.2-4ubuntu2
21.10 impish
Fixed 2.36.1-8ubuntu2.2
20.04 LTS focal
Fixed 2.34-0.1ubuntu9.3
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected

Notes

sbeattie

introduced in 5fea669e9ef0a08804f72bb40f859f239f68c30a (v2.34)

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
util-linux

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