Title

Users customizing attachment security settings must be prevented. (Cat II impact)

Discussion

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.

Check Content

Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2016 -> Security "Prevent users from customizing attachment security settings" is set to "Enabled". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\16.0\outlook Criteria: If the value DisallowAttachmentCustomization is REG_DWORD = 1, this is not a finding.

Fix Text

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

Additional Identifiers

Rule ID: SV-228438r508021_rule

Vulnerability ID: V-228438

Group Title: SRG-APP-000210

Expert Comments

CCIs tied to check.

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