The WinVerifyTrust function in Authenticode Signature Verification 5.1, 6.0, and 6.1 in Microsoft Windows 2000 SP4, Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista Gold, SP1, and SP2, Windows Server 2008 Gold, SP2, and R2, and Windows 7 does not properly use unspecified fields in a file digest, which allows user-assisted remote attackers to execute arbitrary code via a modified (1) Portable Executable (PE) or (2) cabinet (aka .CAB) file that incorrectly appears to have a valid signature, aka "WinVerifyTrust Signature Validation Vulnerability."