Affected: Microsoft Windows 10 Version 20H2, Microsoft Windows Server Version 20H2, Microsoft Windows 10 Version 21H1, Microsoft Windows 10 Version 21H2

Microsoft Windows SMBv3 suffers from a null pointer dereference in versions of Windows prior to the April, 2022 patch set. By sending a malformed FileNormalizedNameInformation SMBv3 request over a named pipe, an attacker can cause a Blue Screen of Death (BSOD) crash of the Windows kernel. For most systems, this attack requires authentication, except in the special case of Windows Domain Controllers, where unauthenticated users can always open named pipes as long as they can establish an SMB session. Typically, after the BSOD, the victim SMBv3 server will reboot.