#VU51639 Incorrect default permissions in Zstandard - CVE-2021-24031

Vulnerability identifier: #VU51639

Vulnerability risk: High

CVSSv4.0: 8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-24031

CWE-ID: CWE-276

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Zstandard
Universal components / Libraries / Libraries used by multiple products

Vendor: Facebook Inc.

Description

The vulnerability allows a remote attacker to escalate privileges on the system.

The vulnerability exists due to incorrect default permissions for files and folders that are set by the application within the command-line utility. A remote attacker can view contents of files and directories or modify them.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Zstandard: 1.4.0

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External links
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=981404
https://github.com/facebook/zstd/issues/1630
https://www.facebook.com/security/advisories/cve-2021-24031

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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