Privilege escalation in Microsoft Kernel Streaming WOW Thunk Service Driver

1) Input validation error

EUVDB-ID: #VU103823

Risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21375

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to insufficient validation of user-supplied input in Kernel Streaming WOW Thunk Service Driver. A local user can pass specially crafted input to the application and gain elevated privileges on the target system.

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: 2008 R2 SP1 - 2025 10.0.26100.2894

CPE2.3

• cpe:2.3:o:microsoft:windows:10_21H2:10.0.19044.5371:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:10_22H2:10.0.19045.5371:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:10_1507:10.0.10240.20890:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:10_1607:10.0.14393.7699:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:10_1809:10.0.17763.6775:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:11_22H2:10.0.22621.4751:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:11_23H2:10.0.22631.4751:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:11_24H2:10.0.26100.2894:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server:2008:6.0.6003.23070:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server:2012:6.2.9200.25273:*:*:*:*:*:*

External links

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21375

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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