#VU49401 Input validation error in Microsoft products - CVE-2021-1647

Vulnerability identifier: #VU49401

Vulnerability risk: Critical

CVSSv4.0: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Red]

CVE-ID: CVE-2021-1647

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
Microsoft Security Essentials
Client/Desktop applications / Antivirus software/Personal firewalls
Windows Defender
Client/Desktop applications / Antivirus software/Personal firewalls
Microsoft System Center Endpoint Protection
Server applications / DLP, anti-spam, sniffers

Vendor: Microsoft

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 RT 8.1 - for Windows 10, Windows 10 1511, Windows 10 1607, Windows Server 2016, Windows 10 1703

Microsoft System Center Endpoint Protection: 2012 R2 - 2012

---

External links
https://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.