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

In today's digital landscape, security is paramount. One crucial aspect of browser security is site isolation, which prevents malicious websites from accessing data from other sites you're visiting. Google Chrome offers a feature called "Strict Site Isolation" (SitePerProcess) to enhance security, and this article will guide you on how to enable it using configuration profiles, specifically within environments managed by Jamf Pro.

Understanding Chrome Flags and Policies

It's essential to understand the difference between chrome://flags and chrome://policy. While chrome://flags allows you to "force" enable experimental features, these settings are not always reliable for enterprise deployments. Chrome policies, accessible via chrome://policy, are the recommended method for managing Chrome settings in a controlled and consistent manner.

The Problem: Specter and Meltdown Vulnerabilities

The initial motivation to enable SitePerProcess often stems from concerns about Specter and Meltdown vulnerabilities. These hardware-level flaws could potentially allow attackers to steal sensitive data. Strict Site Isolation mitigates these risks by ensuring that each website runs in its own process, preventing cross-site data access.

Implementing SitePerProcess via Configuration Profile

The most reliable way to enforce SitePerProcess is through a configuration profile. Here's how you can achieve this using Jamf Pro:

1. Create a Configuration Profile: In Jamf Pro, create a new configuration profile.
2. Custom Settings Payload: Add a "Custom Settings" payload to the profile.
3. Upload the Chrome Plist: Upload a plist file containing the SitePerProcess setting. The correct syntax for the plist should be:

<?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: Define the scope of the profile to apply it to the desired computers or users.

Verifying the Configuration

After deploying the configuration profile, it's crucial to verify that SitePerProcess is enabled correctly.

• Check chrome://policy: Navigate to chrome://policy in Chrome. You should see the "SitePerProcess" policy listed and enabled. This ensures that the policy is being applied correctly.
• Avoid chrome://flags: Do not rely on chrome://flags to verify the setting, as it may not accurately reflect the enforced policies.
• Google's Verification Test: Use Google's official verification test to confirm site isolation is working: https://support.google.com/chrome/a/answer/7581529. This page provides steps to determine if sites are indeed isolated from each other.

Addressing Common Issues

• UI Reporting Discrepancies: The Chrome UI might not always accurately reflect the managed settings. Even if the UI indicates that Strict Site Isolation is not enabled, the policy might still be in effect. Always rely on chrome://policy and Google's verification test for accurate confirmation.
• Configuration Profile Level: Ensure that the configuration profile is applied at the correct level (User or Computer) based on your organizational needs.
• Chrome Version Compatibility: While the setting should work on recent versions of Chrome, ensure you are using a supported version. If issues persist, consider testing with Google Chrome for Enterprise.

Why Configuration Profiles are Preferred

Using configuration profiles offers several advantages:

• Immutability: Configuration profiles enforce settings that are difficult for users to override, ensuring consistent security.
• Centralized Management: Tools like Jamf Pro allow for centralized deployment and management of Chrome policies across an entire organization.
• Reliability: Policies are a more reliable method for enforcing settings compared to command-line flags or manual configurations.

Conclusion

Enabling Strict Site Isolation in Google Chrome is a critical step in enhancing browser security and mitigating potential vulnerabilities. By leveraging configuration profiles and verifying the settings through chrome://policy and Google's verification test, administrators can ensure that SitePerProcess is effectively enforced across their managed environments. Remember to prioritize policy-based configurations over relying solely on Chrome flags for consistent and reliable security.