Details

This policy setting prevents users from overriding the set of attachments blocked by Outlook. If you enable this policy setting users will be prevented from overriding the set of attachments blocked by Outlook. Outlook also checks the ‘Level1Remove’ registry key when this setting is specified. If you disable or do not configure this policy setting, users will be allowed to override the set of attachments blocked by Outlook.

Solution

Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2016 -> Security ‘Prevent users from customizing attachment security settings’ to ‘Enabled’.

Supportive Information

The following resource is also helpful.

• https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_MS_Outlook_2016_V2R1_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: System and Communications Protection.This control applies to the following type of system Windows.

References

• 800-53|SC-18(4)
• CAT|II
• CCI|CCI-001170
• Rule-ID|SV-228438r508021_rule
• STIG-ID|DTOO238
• STIG-Legacy|SV-85779
• STIG-Legacy|V-71155
• Vuln-ID|V-228438

Source

• Tenable.com/audits