Out-of-bounds read in Microsoft Windows and Windows Server - CVE-2025-21212

Vulnerability identifier: #VU103772

CSH Severity: Medium

CVSS v4: 7.1 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2025-21212

CWE-ID: CWE-125

Exploitation vector: Adjecent network

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary condition in the Internet Connection Sharing (ICS). A remote attacker on the local network can send specially crafted packets, trigger an out-of-bounds read error and cause a denial of service condition on the system.

Microsoft Windows
Windows Server

Install updates from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.5487, 10 22H2 10.0.19045.5487, 10 1607 10.0.14393.7785, 10 1809 10.0.17763.6893, 11 22H2 10.0.22621.4890, 11 23H2 10.0.22631.4890, 11 24H2 10.0.26100.3107
Windows Server - addressed in versions 2016 10.0.14393.7785, 2022 23H2 10.0.25398.1425, 2022 10.0.20348.3148, 2022 10.0.20348.3207, 2025 10.0.26100.3107, 2025 10.0.26100.3194

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21212

• Multiple vulnerabilities in Microsoft Internet Connection Sharing (ICS)