Zero-day vulnerability in WinRAR

Input validation error
CVE-2023-38831

Known malware:

DarkMe, GuLoader, RAT

Vulnerability details

Advisory: SB2023082350 - File extension spoofing in WinRAR

Vulnerable component: WinRAR

CVE-ID: CVE-2023-38831

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-20 - Improper input validation

Description:

The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to insufficient validation of file names inside .zip archives. A remote attacker can create a specially crafted archive that contains executable malicious files and spoof their file extension to look like .jpeg or .txt.

Note, the vulnerability is being actively exploited in the wild as of April 2023.

External links:

https://www.group-ib.com/blog/cve-2023-38831-winrar-zero-day/

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.