Input validation

The Authenticode Signature Verification function in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2, R2, and R2 SP1, Windows 7 Gold and SP1, and Windows 8 Consumer Preview does not properly validate the digest of a signed portable executable (PE) file, which allows user-assisted remote attackers to execute arbitrary code via a modified file with additional content, aka “WinVerifyTrust Signature Validation Vulnerability.”