Improper Authentication in Microsoft Windows Remote Desktop Configuration Service

1) Improper Authentication

EUVDB-ID: #VU103825

Risk: High

CVSSv4.0: 4.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2025-21349

CWE-ID: CWE-287 - Improper Authentication

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error when processing authentication requests in Windows Remote Desktop Configuration Service. A remote attacker can perform a man-in-the-middle (MitM) attack, bypass authentication process and gain unauthorized access to the application.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Windows: 10 21H2 10.0.19041.3920 - 11 24H2 10.0.26100.2894

Windows Server: 2016 10.0.14393.10 - 2025 10.0.26100.2894

CPE2.3

• cpe:2.3:o:microsoft:windows:10:21H2_10.0.19041.3920:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:10_21H2:10.0.19043.4529:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:10_21H2:10.0.19044.1147:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:10_21H2:10.0.19044.1149:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:10_21H2:10.0.19044.1151:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:10_21H2:10.0.19044.1165:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:10_21H2:10.0.19044.1200:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:*:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:10_21H2:10.0.19044.1263:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server:2016:10.0.14393.10:*:*:*:*:*:*

External links

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21349

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.