Intune & macOS: .app .pkg .dmg file is blocked by Gatekeeper

Understanding Gatekeeper in macOS and How to Bypass Its Prompts

Gatekeeper is a security feature in macOS designed to protect your system from untrusted software by verifying the source of apps, PKG, and DMG files. When you try to open a file from an unverified source, macOS may show a Gatekeeper prompt, even if the file is legitimate.

What is Gatekeeper?

Gatekeeper controls what software can be installed on your Mac, ensuring that apps are from the App Store or identified developers. It checks for a digital signature to verify that the app hasn’t been tampered with and is safe to run.

How to Resolve Gatekeeper Prompts:

If you encounter a Gatekeeper prompt despite the file being genuine, you can bypass it by checking and removing the quarantine attribute, which Gatekeeper uses to track downloaded files.

1. Check for Quarantine Attribute:

   Run the following command in Terminal to see if the file is quarantined:

xattr /path/to/App.dmg

2. Remove the Quarantine Attribute:

   If the quarantine attribute (`com.apple.quarantine`) is present, remove it by running:

xattr -dr com.apple.quarantine /path/to/App.dmg
   

   

This command removes the quarantine attribute from the file, allowing it to open without Gatekeeper blocking it.

Applying This Solution to .app, .pkg, and .dmg Files

The same process can be applied to any app, PKG, or DMG file. Simply replace the file path in the commands with the appropriate file's path on your system. This method helps bypass Gatekeeper's restrictions when you know the file is safe but still encounter warnings.