CVE-2022-21907

Microsoft released patches addressing CVE-2022-21907, a wormable remote code execution vulnerability in the HTTP Protocol Stack (http.sys) that affects multiple Windows desktop and server versions when HTTP Trailer Support is enabled; due to http.sys being a kernel-mode driver, successful exploitation could lead to complete system compromise. Microsoft and Arctic Wolf report no known in-the-wild exploitation or public PoC at the time of the advisory, and recommend immediate patching and, where applicable, disabling HTTP Trailer Support (Windows Server 2019 / Windows 10 1809) as a temporary mitigation; the bulletin also notes other critical fixes including Exchange and cURL vulnerabilities.