Title

Enable the Missing Root Certificates warning - Outlook. (Cat II impact)

Discussion

When Outlook 2007 accesses a certificate, it validates that it can trust the certificate by examining the root certificate of the issuing CA. If the root certificate can be trusted, then certificates issued by the CA can also be trusted. If Outlook cannot find the root certificate, it cannot validate that any certificates issued by that CA can be trusted. An attacker may compromise a root certificate and then remove the certificate in an attempt to conceal the attack. By default, users are not prompted with a warning or an error when a root certificate cannot be located. By default, Outlook displays a warning message when a CRL is not available.

Check Content

The policy value for User Configuration -> Administrative Templates -> Microsoft Office Outlook 2007 -> Security -> Cryptography -> Signature Status dialog box "Missing root certificates" will be set to "Enabled (error)". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\12.0\Outlook\Security Criteria: If the value SigStatusNoTrustDecision is REG_DWORD = 2, this is not a finding.

Fix Text

The policy value for User Configuration -> Administrative Templates -> Microsoft Office Outlook 2007 -> Security -> Cryptography -> Signature Status dialog box “Missing root certificates” will be set to “Enabled (error)”.

Additional Identifiers

Rule ID: SV-18950r2_rule

Vulnerability ID: V-17756

Group Title:

Expert Comments

CCIs tied to check.

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