“Microsoft Windows fails to properly handle traffic from a malicious server. In particular, Windows fails to properly handle a specially-crafted server response that contains too many bytes following the structure defined in the SMB2 TREE_CONNECT Response structure. By connecting to a malicious SMB server, a vulnerable Windows client system may crash (BSOD) in mrxsmb20.sys. We have confirmed the crash with fully-patched Windows 10 and Windows 8.1 client systems, as well as the server equivalents of these platforms, Windows Server 2016 and Windows Server 2012 R2.”
See Vulnerability Note VU#867968 – Microsoft Windows SMB Tree Connect Response denial of service vulnerabilityI’ve hated M$’s file-sharing since I first looked at the details. Taking a complex protocol and making it ever more complex is a recipe for disaster. Either you have difficulty getting it to work with other systems or you have huge vulnerabilities. I’ve experienced both. Now we’re on SMBv3 and yet again there are problems.
People are recommending blocking the protocol’s ports until M$ gets its act together but that will never happen as long as M$ makes the world’s most complex OS. I’ve done one better. I don’t use SMB at all. I know I have a few applications with client software for it but I don’t have a single share on the LAN, not one. I use Debian GNU/Linux.