#VU50496 Input validation error in ASP.NET Core MVC and Microsoft .NET Core - CVE-2021-26701

Vulnerability identifier: #VU50496

Vulnerability risk: High

CVSSv4.0: 7.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-26701

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
ASP.NET Core MVC
Universal components / Libraries / Software for developers
Microsoft .NET Core
Server applications / Frameworks for developing and running applications

Vendor: Microsoft

Description

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

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

Mitigation
Install updates from vendor's website.

Vulnerable software versions

ASP.NET Core MVC: 2.1.0

Microsoft .NET Core: 3.1

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External links
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26701

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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?

No. We are not aware of malware exploiting this vulnerability.