#VU61394 UNIX symbolic link following in libarchive - CVE-2021-31566

Vulnerability identifier: #VU61394

Vulnerability risk: Low

CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-31566

CWE-ID: CWE-61

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
libarchive
Client/Desktop applications / Software for archiving

Vendor: libarchive

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

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=2024237

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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.