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."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A7164
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2010/ms10-020