Disable Screen Saver Hot Corners

What the screen saver hot corners disabler does

This Automox Worklet™ disables screen saver hot corners on macOS endpoints. Hot corners are a macOS feature that allows users to trigger actions (like disabling the screen saver) by moving the cursor to specific corners of the display.

The Worklet checks all four corners (top-left, top-right, bottom-left, and bottom-right) for hot corner settings that disable the screen saver. When a problematic hot corner is detected, the Worklet disables it by resetting the preference to zero and refreshing the Dock application.

This targeted approach verifies that legitimate hot corner functionality remains available while preventing the specific configuration that bypasses screen locks.

Why remove screen saver hot corner shortcuts

Attackers with brief physical access can bypass automatic screen lock policies through hot corner gestures. Hot corners that instantly disable the screen saver or prevent automatic screen locking create security vulnerabilities by allowing unauthorized users to maintain access to unattended endpoints that should automatically lock after a timeout period.

Security policies requiring automatic screen lock after inactivity become ineffective when users configure hot corners to disable screen savers. Users who leverage hot corners to avoid reauthentication inadvertently leave endpoints accessible to anyone with physical access. Disabling hot corners enforces consistent automatic lock behavior across your macOS fleet.

Organizations with compliance requirements for physical security controls must disable hot corners. HIPAA, PCI-DSS, and SOC 2 frameworks require endpoints to automatically lock after brief inactivity periods. Hot corners that prevent this locking create compliance violations during security audits.

How hot corner detection and remediation works

1. Evaluation phase: The Worklet reads the current user's Dock preferences stored in `com.apple.dock` for all four hot corner settings (wvous-tl-corner, wvous-bl-corner, wvous-tr-corner, wvous-br-corner). If any corner is set to value 6 (disable screen saver), the Worklet exits with a non-compliant status, triggering remediation.

2. Remediation phase: For each detected problematic hot corner, the Worklet writes the value 0 to the preference using the macOS `defaults write` command, disabling that corner's functionality. The Worklet then runs `killall Dock` to refresh the Dock application and apply changes immediately without requiring a restart.

Hot corner remediation requirements

• macOS Big Sur, Monterey, or later (tested on M1 and Intel architectures)

• Administrator or sudo privileges to modify system preferences

• The ability to detect and refresh the Dock application (no restart required)

• A logged-in user session (the Worklet operates in the context of the console user)

Expected screen saver behavior

After remediation, hot corners are disabled and cannot trigger or prevent screen saver activation. Endpoints automatically lock after the configured inactivity timeout regardless of mouse cursor position. Users can still manually activate the screen saver but cannot use hot corner shortcuts to circumvent automatic locking. This results in consistent automatic lock behavior across your macOS fleet, eliminating the security vulnerability that allows physical access bypass.

The Worklet confirms hot corners are disabled through its evaluation phase. IT operations teams can verify the setting by checking Desktop and Screen Saver preferences or reviewing Worklet execution results in the Automox console. Subsequent evaluations report compliance, demonstrating that hot corner bypass capabilities remain eliminated.

How to validate disable screen saver hot corners changes

1. Run this Worklet on a pilot macOS endpoint and review evaluation output for disable screen saver hot corners.

2. Confirm Automox activity logs show successful completion and exit code 0.

3. Verify endpoint state using checks aligned to evaluation script logic, such as exit.

4. Validate remediation effects from script operations such as eval, killall, exit, then rerun evaluation for compliance.