18.9.24.2 Ensure 'Default Action and Mitigation Settings: Banned Functions' is set to 'Enabled'

Information

This setting configures the default action after detection and advanced ROP mitigation.

The recommended state for this setting is:

- Default Action and Mitigation Settings - 'Enabled'
- Deep Hooks - 'Enabled'
- Anti Detours - 'Enabled'
- Banned Functions - 'Enabled'
- Exploit Action -' User Configured'

Rationale:
These advanced mitigations for ROP mitigations apply to all configured software in EMET:

- Deep Hooks protects critical APIs and the subsequent lower level APIs used by the top level critical API.
- Anti Detours renders ineffective exploits that evade hooks by executing a copy of the hooked function prologue and then jump to the function past the prologue.
- Banned Functions will block calls to 'ntdll!LdrHotPatchRoutine' to mitigate potential exploits abusing the API.

Solution

To establish the recommended configuration via GP, set the following UI path to 'Enabled:'


Computer Configuration\Policies\Administrative Templates\Windows Components\EMET\Default Action and Mitigation Settings

Note: This Group Policy path does not exist by default. An additional Group Policy template ('EMET.admx/adml') is required - it is included with Microsoft Enhanced Mitigation Experience Toolkit (EMET).

Impact:
The advanced mitigations available in EMET will be enabled and actively applied to all software they are configured for.

See Also

https://workbench.cisecurity.org/files/1937