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CVE Number Vulnerability Product Severity Date
MS15-031 Vulnerability in Schannel Could Allow Security Feature Bypass (3046049) Windows Server Important 11-03-2015

Technical Information

Brief overview of the risk:
This security update resolves a vulnerability in Microsoft Windows that facilitates exploitation of the publicly disclosed FREAK technique, an industry-wide issue that is not specific to Windows operating systems. The vulnerability could allow a man-in-the-middle (MiTM) attacker to force the downgrading of the key length of an RSA key to EXPORT-grade length in a TLS connection. Any Windows system using Schannel to connect to a remote TLS server with an insecure cipher suite is affected.

Detailed Information on the risk:

A security feature bypass vulnerability exists in Secure Channel (Schannel) that is caused by an issue in the TLS state machine whereby a client system accepts an RSA key with a shorter key length than the originally negotiated key length. The vulnerability facilitates exploitation of the publicly disclosed FREAK technique, which is an industry-wide issue that is not specific to Windows operating systems.


Further information on this exploit is available at : MS15-031

Windows Server 2003 Service Pack 2 
Windows Server 2003 x64 Edition Service Pack 2 
Windows Server 2003 with SP2 for Itanium-based Systems 
Windows Vista Service Pack 2 
Windows Vista x64 Edition Service Pack 2 
Windows Server 2008 for 32-bit Systems Service Pack 2 
Windows Server 2008 for x64-based Systems Service Pack 2 
Windows Server 2008 for Itanium-based Systems Service Pack 2 
Windows 7 for 32-bit Systems Service Pack 1 
Windows 7 for x64-based Systems Service Pack 1 
Windows Server 2008 R2 for x64-based Systems Service Pack 1 
Windows Server 2008 R2 for Itanium-based Systems Service Pack 1 
Windows 8 for 32-bit Systems 
Windows 8 for x64-based Systems 
Windows 8.1 for 32-bit Systems 
Windows 8.1 for x64-based Systems 
Windows Server 2012 and Windows Server 2012 R2
Windows Server 2012 R2 
Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) 
Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) 
Windows Server 2012 (Server Core installation) 
Windows Server 2012 R2 (Server Core installation)

Affected Software

Windows Server 2003 Service Pack 2 
Windows Server 2003 x64 Edition Service Pack 2 
Windows Server 2003 with SP2 for Itanium-based Systems 
Windows Vista Service Pack 2 
Windows Vista x64 Edition Service Pack 2 
Windows Server 2008 for 32-bit Systems Service Pack 2 
Windows Server 2008 for x64-based Systems Service Pack 2 
Windows Server 2008 for Itanium-based Systems Service Pack 2 
Windows 7 for 32-bit Systems Service Pack 1 
Windows 7 for x64-based Systems Service Pack 1 
Windows Server 2008 R2 for x64-based Systems Service Pack 1 
Windows Server 2008 R2 for Itanium-based Systems Service Pack 1 
Windows 8 for 32-bit Systems 
Windows 8 for x64-based Systems 
Windows 8.1 for 32-bit Systems 
Windows 8.1 for x64-based Systems 
Windows Server 2012 and Windows Server 2012 R2
Windows Server 2012 R2 
Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) 
Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) 
Windows Server 2012 (Server Core installation) 
Windows Server 2012 R2 (Server Core installation)