Vulnerability identifier: #VU86459

Vulnerability risk: High

CVSSv3.1: 8.4 [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]

CVE-ID: CVE-2024-21338

CWE-ID: CWE-119

Exploitation vector: Local

Exploit availability: Yes

Vulnerable software:
Windows
Operating systems & Components / Operating system
Windows Server
Operating systems & Components / Operating system

Vendor: Microsoft

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.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Windows: 10 1809 10.0.17763.1, 11 21H2 10.0.22000.194, 10 22H2 10.0.19045.2130, 10 21H2 10.0.19044.1288, 10 21H1 10.0.19043.985, 10 1507 10.0.10240.16405, 10 20H2 10.0.19042.572, 10 2004 10.0.19041.264, 10 1909 10.0.18363.476, 10 1903 10.0.18362.116, 10 1803 10.0.17134.48, 10 1709 10.0.16299.19, 10 1703 10.0.15063.138, 10 1607 10.0.14393.10, 10 1511 10.0.10586.3, 11 23H2 10.0.22631.2428, 11 22H2 10.0.22621.521

Windows Server: 2019 10.0.17763.1 - 2022 23H2

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

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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?

Yes. This vulnerability is being exploited in the wild.