The United States Computer Emergency Readiness Team (US-CERT) has releases an official Advisory yesterday. Microsoft Windows contains a memory corruption bug in the handling of SMB traffic, which may allow a remote, unauthenticated attacker to cause a denial of service or potentially execute arbitrary code on a vulnerable system. Microsoft Windows fails to properly handle traffic from a malicious server. In particular, Windows fails to properly handle a 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. In short – some Windows versions (clients an servers) contains a memory corruption bug in the code to handle SMB data traffic. The bug is contained within the kernel file mrxsmb20.sys. US-CERT writes, that the bug may be used by unauthenticated attacker to cause a denial of service (aka B