CVE-2024-38187: 
vulnerability analysis and mitigation

Windows Kernel-Mode Driver Elevation of Privilege Vulnerability (CVE-2024-38187) is a security flaw discovered in Microsoft Windows CLIPSP.SYS driver, which is used to implement Client License System Policy on Windows 10 and 11. The vulnerability was disclosed on August 13, 2024, and affects multiple versions of Windows 10, Windows 11, and Windows Server (Microsoft Advisory, Talos Report).

The vulnerability is an out-of-bounds read vulnerability in the License Update Field Type 0x20 functionality of Microsoft Windows CLIPSP.SYS. It exists in versions 10.0.22621 Build 22621, 10.0.26080.1, and 10.0.26085.1. The issue occurs when handling various license field types during the processing of license blobs. The vulnerability has a CVSS v3.1 base score of 7.8 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H and is classified under CWE-822 (Untrusted Pointer Dereference) (NVD, Talos Report).

The vulnerability can lead to elevation of privilege and denial of service conditions. When exploited, a specially crafted license blob can trigger an access violation leading to a blue screen that could become recurring if the license file successfully installs (Talos Report).

Microsoft has released security updates to address this vulnerability. The fixes are available through various KB updates including KB5040434 for Windows 10 1607, KB5040430 for Windows 10 1809, KB5040427 for Windows 10 21H2/22H2, KB5040442 for Windows 11 22H2/23H2, and corresponding updates for Windows Server versions (Rapid7).