Enforcing Strict Site Isolation in Google Chrome: A Configuration Profile Approach

In today's digital landscape, security vulnerabilities like Spectre and Meltdown pose significant threats. One way to mitigate these risks in Google Chrome is by enabling Strict Site Isolation, also known as SitePerProcess. This ensures that websites are rendered in separate processes, preventing malicious scripts from one site from accessing data from another. While manually enabling this feature via chrome://flags might seem straightforward, a more robust and manageable approach involves utilizing configuration profiles.

Understanding Chrome Flags vs. Chrome Policy

It's crucial to understand the distinction between chrome://flags and chrome://policy. chrome://flags offers a way to experiment with and "force" enable features, but these settings are not intended for enterprise-level deployments. Chrome policies, on the other hand, are designed for managed environments and provide a centralized way to enforce settings across multiple Chrome instances. These policies can be verified by navigating to chrome://policy in Chrome.

The Configuration Profile Method: A Reliable Solution

The recommended method for enabling Strict Site Isolation in a managed environment is through a configuration profile, especially when using a management tool like Jamf Pro. Let's delve into how this can be achieved:

1. Creating a Configuration Profile: Within Jamf Pro, create a new configuration profile.

2. Custom Settings Payload: Add a "Custom Settings" payload to the configuration profile. This allows you to upload a Chrome plist file containing the desired settings.

3. The Chrome Plist: The plist file should contain the SitePerProcess key set to <true/>. Here's an example of what the plist file should look like:

   <?xml version="1.0" encoding="UTF-8"?>
   <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
   <plist version="1.0">
   <dict>
     <key>SitePerProcess</key>
     <true/>
   </dict>
   </plist>
   

4. Scope and Deploy: Scope the configuration profile to the desired computers or user groups. Jamf Pro will then deploy the profile, enforcing the Strict Site Isolation policy.

Verifying the Policy Application

After deploying the configuration profile, it's essential to verify that the policy has been successfully applied. Here's how:

• Navigate to chrome://policy: Open Google Chrome on a managed device and navigate to chrome://policy.
• Check for the SitePerProcess Policy: Look for the SitePerProcess policy in the list. If the configuration profile was successfully deployed, the policy should be listed with a status of "Enabled".

Important Note: As noted in the original forum discussion, the Chrome UI (specifically chrome://flags) might not reflect the managed settings. Don't rely on chrome://flags to verify the policy.

Troubleshooting Tips

• Configuration Profile Level: Ensure the configuration profile is applied at the computer level for consistent enforcement. While user-level profiles might seem applicable, computer-level ensures that the setting is enforced regardless of the logged-in user.
• Chrome Version Compatibility: Verify that you are using a supported version of Google Chrome. While the forum discussion mentions Chrome 63.x, it's always best to use the latest stable version for optimal compatibility and security.
• Testing with Google's Verification Site: Google provides a test site for verifying site isolation: https://support.google.com/chrome/a/answer/7581529. Use this site to confirm that Strict Site Isolation is functioning correctly.
• Chrome for Enterprise: While standard Google Chrome should respect the policy, consider using Google Chrome for Enterprise for more robust management capabilities.

Why Configuration Profiles are Preferred

• Centralized Management: Configuration profiles provide a centralized way to manage Chrome settings across your organization.
• Immutability: Settings enforced through configuration profiles are generally immutable, preventing users from accidentally or intentionally disabling them.
• Consistency: Ensures a consistent security posture across all managed Chrome instances.

By leveraging configuration profiles, you can effectively enforce Strict Site Isolation in Google Chrome, enhancing the security of your environment and mitigating potential threats. Remember to verify the policy application and utilize Google's verification site to ensure that site isolation is functioning as expected. This approach offers a robust and manageable solution for safeguarding your organization against modern web-based threats.

This article references the Jamf Nation Community, a valuable resource for IT professionals managing Apple devices. For more on Jamf Pro, see Jamf Pro. You can learn more about Jamf and its solutions on their website.