Affected: Microsoft Security Essentials, Microsoft System Center, Microsoft Forefront Endpoint Protection, Microsoft Windows Defender on Windows 7 for 32-bit Systems, Microsoft Windows Defender on Windows 7 for x64-based Systems, Microsoft Windows Defender on Windows Server 2008 R2 for x64-based Systems (Server Core installation), Microsoft Windows Defender on Windows Server 2008 R2 for Itanium-Based Systems, Microsoft Windows Defender on Windows Server 2008 R2 for x64-based Systems, Microsoft Windows Defender on Windows Server 2008 for 32-bit Systems (Server Core installation), Microsoft Windows Defender on Windows Server 2012 and 32 more

A denial of service vulnerability exists when Microsoft Defender improperly handles files, aka 'Microsoft Defender Denial of Service Vulnerability'.