Title

Read signed email as plain text must be enforced. (Cat II impact)

Discussion

Outlook can display e-mail messages and other items in three formats: plain text, Rich Text Format (RTF), and HTML. By default, Outlook displays digitally signed e-mail messages in the format they were received in.

Check Content

The policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2010 -> Outlook Options -> Preferences -> E-mail Options “Read signed e-mail as plain text” must be set to “Enabled”. Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\14.0\outlook\options\mail Criteria: If the value ReadSignedAsPlain is REG_DWORD = 1, this is not a finding.

Fix Text

Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2010 -> Outlook Options -> Preferences -> E-mail Options “Read signed e-mail as plain text” to “Enabled”.

Additional Identifiers

Rule ID: SV-33519r1_rule

Vulnerability ID: V-17771

Group Title: DTOO215 - Read signed EMail as plain text

Expert Comments

CCIs tied to check.

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