Title

Set security feature to always warn about invalid signature - Outlook. (Cat II impact)

Discussion

By default, if users open e-mail messages that include invalid digital signatures, Outlook 2007 displays a warning dialog box. Users can decide whether they want to be warned about invalid signatures in the future. If users are not notified about invalid signatures, they might be prevented from detecting a fraudulent signature sent by a malicious person.

Check Content

The policy value for User Configuration -> Administrative Templates -> Microsoft Office Outlook 2007 -> Security -> Cryptography “Signature Warning” will be set to “Enabled (Always warn about invalid signatures)”. 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 WarnAboutInvalid is REG_DWORD = 1, this is not a finding.

Fix Text

The policy value for User Configuration -> Administrative Templates -> Microsoft Office Outlook 2007 -> Security -> Cryptography “Signature Warning” will be set to “Enabled (Always warn about invalid signatures)”.

Additional Identifiers

Rule ID: SV-19032r1_rule

Vulnerability ID: V-17803

Group Title:

Expert Comments

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