Multiple vulnerabilities in libarchive

Published: 2022-03-15

Risk	Low
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2021-31566 CVE-2021-23177
CWE-ID	CWE-61
Exploitation vector	Local
Public exploit	N/A
Vulnerable software Subscribe	libarchive Client/Desktop applications / Software for archiving
Vendor	libarchive

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) UNIX symbolic link following

EUVDB-ID: #VU61394

Risk: Low

CVSSv3.1: 6.4 [CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-31566

CWE-ID: CWE-61 - UNIX Symbolic Link (Symlink) Following

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a symlink following issue when extracting files from the archive. A local user can create a specially crafted symbolic link to a critical file on the system, place it into an archive and modify modes, times, access control lists, and flags of a file outside of the archive.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

libarchive: 3.0 - 3.5.1

External links

http://bugzilla.redhat.com/show_bug.cgi?id=2024237

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.

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to open a a specially crafted archive.

The attacker would have to login to the system and perform certain actions in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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

2) UNIX symbolic link following

EUVDB-ID: #VU61393