The SMB client in Microsoft Windows Server 2008 R2 and Windows 7 does not properly validate fields in SMB transaction responses, which allows remote SMB servers and man-in-the-middle attackers to execute arbitrary code or cause a denial of service (memory corruption and reboot) via a crafted (1) SMBv1 or (2) SMBv2 response, aka "SMB Client Transaction Vulnerability."
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.