Read signed email as plain text must be enforced.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-251865 | DTOO215 | SV-251865r811186_rule | CCI-000366 | medium |
| Description | ||||
| Outlook can display email messages and other items in three formats: plain text, Rich Text Format (RTF), and HTML. By default, Outlook displays digitally signed email messages in the format which they were received. | ||||
| STIG | Date | |||
| Microsoft Outlook 2016 Security Technical Implementation Guide | 2022-03-11 | |||
Details
Check Text (C-251865r811186_chk)
Verify the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Outlook Options >> Preferences >> E-mail Options "Read signed e-mail as plain text" is set to "Enabled".
Procedure: Use the Windows Registry Editor to navigate to the following key:
HKCU\Software\Policies\Microsoft\Office\16.0\outlook\options\mail
Criteria: If the value ReadSignedAsPlain is REG_DWORD = 1, this is not a finding.
Fix Text (F-55279r811185_fix)
Set the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Outlook Options >> Preferences >> E-mail Options "Read signed e-mail as plain text" to "Enabled".