In the Patch Tuesday update of April 2024, Microsoft released a fix for CVE-2024-20693, a vulnerability we reported. This vulnerability allowed manipulating the cached signature signing level of an executable or DLL. In this post, we’ll describe how we found this issue and what the impact could be on Windows 11. Background Last year, we started a project to improve our knowledge of Windows internals, specifically about local vulnerabilities such as privilege escalation.