Remote code execution in Microsoft MSHTML

1) Code Injection

EUVDB-ID: #VU56377

Risk: Critical

CVSSv3.1: 8.4 [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]

CVE-ID: CVE-2021-40444

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation within the MSHTML component. A remote attacker can create a specially crafted Office document with a malicious ActiveX control inside, trick the victim into opening the document and execute arbitrary code on the system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

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

Mitigation

Install update from vendor's website.

Vulnerable software versions

Windows: 8.1 - 10 S

Windows Server: 2008 - 2019 2004

Microsoft Internet Explorer: 11

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-40444

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?

Yes. This vulnerability is being exploited in the wild.