Title

Legacy format signatures should be enabled - Office (Cat II impact)

Discussion

By default, 2007 Office applications use the XML–based XMLDSIG format to attach digital signatures to documents, including Office 97-2003 binary documents. XMLDSIG signatures are not recognized by Office 2003 applications or previous versions. If an Office 2003 user opens an Excel, PowerPoint, or Word binary document with an XMLDSIG signature attached, the signature will be lost.

Check Content

The policy value for User Configuration -> Administrative Templates -> Microsoft Office 2007 system -> Signing “Legacy format signatures” will be set to “Enabled”. Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\12.0\Common\Signatures Criteria: If the value XPCompatibleSignatureFormat is REG_DWORD = 1, this is not a finding.

Fix Text

The policy value for User Configuration -> Administrative Templates -> Microsoft Office 2007 system -> Signing “Legacy format signatures” will be set to “Enabled”. "Note: Group Policy Administrative Templates are available from the www.microsoft.com download site. The MS Office 2007 System (Office12.adm) is included in the AdminTemplates.exe file. This template provides the mechanisms to incorporate Microsoft Office 2007 System policies via the Microsoft Group Policy Editor (gpedit.msc)." "Note: If the Microsoft Group Policy Editor (gpedit.msc) is not used to incorporate the remediation to this vulnerability the Microsoft Registry Editor (regedit.exe) may be used to create the registry key and value required."

Additional Identifiers

Rule ID: SV-18937r1_rule

Vulnerability ID: V-17749

Group Title:

Expert Comments

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