Ubuntu update for util-linux

Published: 2022-02-09

Risk	Low
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2021-3995 CVE-2021-3996
CWE-ID	CWE-264
Exploitation vector	Local
Public exploit	N/A
Vulnerable software Subscribe	Ubuntu Operating systems & Components / Operating system util-linux (Ubuntu package) Operating systems & Components / Operating system package or component mount (Ubuntu package) Operating systems & Components / Operating system package or component
Vendor	Canonical Ltd.

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU60004

Risk: Low

CVSSv3.1: 2.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3995

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a local user to bypass implemented security restrictions.

The vulnerability exists due to improper parsing of the /proc/self/mountinfo file in libmount. A local user can unmount other user's filesystems that are either world-writable themselves or mounted in a world-writable directory.

Mitigation

Update the affected package util-linux to the latest version.

Vulnerable software versions

Ubuntu: 20.04 - 21.10

util-linux (Ubuntu package): before 2.36.1-8ubuntu2.2

mount (Ubuntu package): before 2.36.1-8ubuntu2.2

External links

http://ubuntu.com/security/notices/USN-5279-1

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU60005