Zero-day vulnerability in Windows

Buffer overflow
CVE-2024-21338

Vulnerability details

Advisory: SB2024021367 - Multiple vulnerabilities in Microsoft Windows Kernel

Vulnerable component: Windows

CVE-ID: CVE-2024-21338

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

CWE-ID: CWE-119 - Memory corruption

Description:

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

The vulnerability exists due to a boundary error within the appid.sys AppLocker driver. A local user can trigger memory corruption and execute arbitrary code with elevated privileges.

Note, the vulnerability is being actively exploited in the wild.

External links:

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21338
https://decoded.avast.io/janvojtesek/lazarus-and-the-fudmodule-rootkit-beyond-byovd-with-an-admin-to...

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.