Remote code execution in Microsoft Defender

1) Input validation error

EUVDB-ID: #VU49401

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-2021-1647

CWE-ID: CWE-20 - Improper input validation

Exploit availability: Yes

Description

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

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can pass specially crafted input to the application and execute arbitrary code on the system.

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

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Security Essentials: All versions

Windows Defender: for Windows 8.1 - on Windows Server 2012

Microsoft System Center Endpoint Protection: 2012 - 2012 R2

CPE2.3

• cpe:2.3:a:microsoft:microsoft_security_essentials:*:*:*:*:*:*:*:*
• cpe:2.3:a:microsoft:windows_defender:for Windows 10, Windows 10 1511, Windows 10 1607, Windows Server 2016, Windows 10 1703:*:*:*:*:*:*:*
• cpe:2.3:a:microsoft:windows_defender:for Windows Server 2019:*:*:*:*:*:*:*
• cpe:2.3:a:microsoft:windows_defender:on Windows 7 for 32-bit Systems Service Pack 1:*:*:*:*:*:*:*
• cpe:2.3:a:microsoft:microsoft_system_center_endpoint_protection:*:*:*:*:*:*:*:*
• cpe:2.3:a:microsoft:microsoft_system_center_endpoint_protection:2012 R2:*:*:*:*:*:*:*
• cpe:2.3:a:microsoft:microsoft_system_center_endpoint_protection:2012:*:*:*:*:*:*:*

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1647

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.