Information
This policy setting configures whether the
WinVerifyTrust
function performs strict Windows Authenticode signature verification for Portable Executable files (PE files). If enabled, PE files will be considered 'unsigned' if Windows identifies content in them that does not conform to the Authenticode specification.
The recommended state for this setting is: Enabled
A remote code execution vulnerability exists in the way that the
WinVerifyTrust
function handles Windows Authenticode signature verification for portable executable (PE) files. For more information on this vulnerability, visit
CVE-2013-3900 - Security Update Guide - Microsoft - WinVerifyTrust Signature Validation Vulnerability
.
Solution
To establish the recommended configuration via GP, set the following UI path to Enabled :
Computer Configuration\Policies\Administrative Templates\MS Security Guide\Enable Certificate Padding
Note: This Group Policy path does not exist by default. An additional Group Policy template ( SecGuide.admx/adml ) is required - it is available from Microsoft at
this link
.
Impact:
Microsoft recommends that installers are built to only extract content from validated portions of signed files. Some installers do not follow this guidance and therefore may be negatively impacted by this setting.