Privilege escalation in Microsoft Windows Cloud Files Mini Filter Driver

1) Out-of-bounds read

EUVDB-ID: #VU102710

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-2025-21271

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: No

Description

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

The vulnerability exists due to a boundary condition in Windows Cloud Files Mini Filter Driver. A local user can trigger an out-of-bounds read error 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: 2016 10.0.14393.10 - 2022 10.0.20348.2966

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://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21271

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.