How to Enforce Strict Site Isolation in Google Chrome Using Configuration Profiles

In today's digital landscape, security is paramount. One crucial aspect of web browser security is site isolation, which prevents malicious websites from accessing data from other sites. Google Chrome offers a feature called "Strict Site Isolation" (SitePerProcess) to enhance security. This article explores how to effectively enable and enforce this feature across managed Chrome deployments using configuration profiles, specifically within environments utilizing Jamf Pro.

Understanding Strict Site Isolation

Strict Site Isolation ensures that each website runs in its own process, preventing cross-site data access. This mitigates the risks associated with vulnerabilities like Spectre and Meltdown, which can be exploited to steal sensitive information. While Chrome offers flags to enable this feature, relying solely on these flags can be unreliable. Google recommends using Chrome policies for a more robust and manageable solution.

The Configuration Profile Method: A Reliable Approach

The most effective method to enforce Strict Site Isolation is through configuration profiles. Here's how you can achieve this:

1. Create a Configuration Profile: Use a tool like Jamf Pro to create a new configuration profile.
2. Custom Settings Payload: Within the profile, add a custom settings payload specifically for Google Chrome.
3. Upload the Chrome .plist: Upload a .plist file containing the configuration settings. This file will enforce the SitePerProcess policy.

Here's an example of the .plist file content:

<?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 the Profile: Deploy the configuration profile to your target Macs or user groups. Using Jamf Pro, you can scope it out based on your organizational needs.

Verifying the Configuration

After deploying the configuration profile, it's crucial to verify that Strict Site Isolation is indeed enabled. Here's how:

• Chrome://Policy: Navigate to chrome://policy in Chrome. This page displays all active Chrome policies, including those enforced through configuration profiles. Verify that SitePerProcess is listed and enabled.
• Google's Test Site: Visit https://support.google.com/chrome/a/answer/7581529, which provides steps to "Verify site isolation". This test confirms whether sites are properly isolated.

Important Note: Do not rely solely on chrome://flags to verify the setting. This page is intended for experimenting with features and doesn't accurately reflect policies enforced via configuration profiles.

Addressing Common Challenges

Users may encounter situations where the Chrome UI doesn't reflect the managed settings. This can be misleading, as the UI might indicate that Strict Site Isolation is disabled even when it's active through policy. Always use chrome://policy or Google’s test site to confirm the actual status.

Why Configuration Profiles are Preferred

While command-line flags can temporarily enable features, they are not a reliable solution for enterprise deployments. Configuration profiles offer several advantages:

• Centralized Management: Configuration profiles allow administrators to centrally manage and enforce policies across multiple devices.
• Immutability: Settings enforced through configuration profiles are immutable, meaning users cannot easily override them.
• Consistency: Ensures consistent security settings across your entire organization.
• Integration with MDM: Seamless integration with Mobile Device Management (MDM) solutions like Jamf Pro, which are designed for managing Apple devices. Consider exploring Jamf Integrations for other compatibility options.

Conclusion

Enforcing Strict Site Isolation in Google Chrome is a vital step in securing your environment against modern web-based threats. By utilizing configuration profiles and verifying the settings through chrome://policy, administrators can confidently deploy this critical security feature across their organizations. This approach ensures a consistent and manageable security posture, protecting users from potential vulnerabilities.