Title

Missing Root Certificates warning must be enforced. (Cat II impact)

Discussion

When Outlook 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, Outlook displays a warning message when a CRL is not available.

Check Content

The policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2010 -> Security -> Cryptography -> Signature Status dialog box "Missing root certificates" must be set to "Enabled (Error)". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\14.0\outlook\security Criteria: If the value SigStatusNoTrustDecision is REG_DWORD = 2, this is not a finding.

Fix Text

Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2010 -> Security -> Cryptography -> Signature Status dialog box "Missing root certificates" to "Enabled (Error)".

Additional Identifiers

Rule ID: SV-242080r961893_rule

Vulnerability ID: V-242080

Group Title: SRG-APP-000605

Expert Comments

CCIs tied to check.

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