Title

The encryption type for password protected Open XML files must be set. (Cat II impact)

Discussion

If unencrypted files are intercepted, sensitive information in the files can be compromised. To protect information confidentiality, Office application files can be encrypted and password protected. Only users who know the correct password will be able to decrypt such files.

Check Content

The policy value for User Configuration -> Administrative Templates -> Microsoft Office 2010 -> Security Settings “Encryption type for password protected Office Open XML files” must be set to “Enabled (Microsoft Enhanced RSA and AES Cryptographic Provider,AES 256,256)”. Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\14.0\common\security Criteria: If the value OpenXMLEncryption is REG_SZ = “Microsoft Enhanced RSA and AES Cryptographic Provider,AES 256,256”, this is not a finding.

Fix Text

Set the policy value for User Configuration -> Administrative Templates -> Microsoft Office 2010 -> Security Settings “Encryption type for password protected Office Open XML files” to “Enabled (Microsoft Enhanced RSA and AES Cryptographic Provider,AES 256,256)”.

Additional Identifiers

Rule ID: SV-33465r3_rule

Vulnerability ID: V-17619

Group Title: DTOO189 - Encryption Type for Pwd Protected files

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.