CVE-2024-6778: Google Chrome RCE Vulnerability

CVE-2024-6778 Overview

CVE-2024-6778 is a race condition vulnerability in the DevTools component of Google Chrome prior to version 126.0.6478.182. This flaw allows an attacker who convinces a user to install a malicious extension to inject scripts or HTML into a privileged page via a crafted Chrome Extension. The vulnerability has been classified with high severity by Chromium security.

Critical Impact

Successful exploitation could allow attackers to execute arbitrary scripts or inject malicious HTML into privileged browser pages, potentially leading to complete compromise of confidentiality, integrity, and availability of browser sessions and user data.

Affected Products

• Google Chrome versions prior to 126.0.6478.182
• All platforms running vulnerable Chrome versions (Windows, macOS, Linux)
• Chrome-based browsers using the affected Chromium codebase

Discovery Timeline

• July 16, 2024 - CVE-2024-6778 published to NVD
• December 26, 2024 - Last updated in NVD database

Technical Details for CVE-2024-6778

Vulnerability Analysis

This vulnerability stems from a race condition (CWE-362, CWE-366) within the DevTools component of Google Chrome. Race conditions occur when the timing or ordering of events affects the correctness of a program, allowing an attacker to exploit the window between two operations that should be atomic.

In this case, the flaw exists in how Chrome handles extension interactions with DevTools functionality. The race condition creates an opportunity for a malicious extension to inject unauthorized scripts or HTML content into privileged browser pages—pages that normally have elevated permissions and access to sensitive browser internals.

The attack requires user interaction in the form of installing a malicious extension. Once installed, the extension can leverage the race condition to bypass security boundaries and inject content into areas of the browser that should be protected from extension access.

Root Cause

The root cause is a race condition in the DevTools implementation that fails to properly synchronize access when handling requests from Chrome extensions. This timing flaw allows attackers to exploit the gap between security checks and the actual execution of privileged operations, enabling script and HTML injection into protected pages.

Attack Vector

The attack vector is network-based and requires user interaction. The exploitation flow involves:

1. Social Engineering: An attacker must convince a victim to install a malicious Chrome extension, potentially through phishing, fake update prompts, or compromised extension marketplace listings
2. Extension Installation: Once the user installs the malicious extension, it gains the ability to interact with browser APIs
3. Race Condition Exploitation: The extension exploits the timing vulnerability in DevTools to inject malicious scripts or HTML into privileged pages
4. Privilege Escalation: The injected content executes with elevated privileges, potentially accessing sensitive browser data, credentials, or session information

The vulnerability requires high attack complexity due to the race condition's timing-dependent nature, but successful exploitation yields high impact across confidentiality, integrity, and availability.

Detection Methods for CVE-2024-6778

Indicators of Compromise

• Unexpected or suspicious Chrome extensions installed without user knowledge
• Unusual DevTools activity or processes spawning unexpectedly
• Anomalous script execution in privileged Chrome pages (chrome://, about:, or extension pages)
• Browser behavior changes such as unauthorized modifications to settings or homepage

Detection Strategies

• Monitor for newly installed Chrome extensions, especially from unknown or untrusted sources
• Implement endpoint detection rules to identify malicious extension behaviors
• Review Chrome extension permissions and audit extensions with broad access rights
• Deploy SentinelOne Singularity to detect and block malicious extension activity and script injection attempts

Monitoring Recommendations

• Enable Chrome Enterprise policies to log extension installations and activities
• Monitor browser process behaviors for anomalous parent-child process relationships
• Implement network monitoring to detect command-and-control communications from compromised browsers
• Configure alerts for modifications to privileged browser pages or Chrome internal URLs

How to Mitigate CVE-2024-6778

Immediate Actions Required

• Update Google Chrome to version 126.0.6478.182 or later immediately
• Audit all installed Chrome extensions and remove any suspicious or unnecessary extensions
• Implement Chrome Enterprise policies to restrict extension installations to trusted sources only
• Enable automatic Chrome updates to ensure timely patching of future vulnerabilities

Patch Information

Google has addressed this vulnerability in Chrome version 126.0.6478.182. The fix was announced in the Google Chrome Stable Update. Users should update their browsers immediately. Additional technical details can be found in the Chromium Issue Tracker Entry.

To verify your Chrome version, navigate to chrome://settings/help in your browser. Chrome should automatically download and apply updates when available. Organizations using managed Chrome deployments should push the updated version through their enterprise management tools.

Workarounds

• Restrict Chrome extension installations to enterprise-approved extensions only using Chrome policies
• Disable or limit DevTools access for non-developer users via enterprise configuration
• Implement strict browser security policies that prevent installation of extensions from outside the Chrome Web Store
• Use browser isolation solutions to contain potential exploitation attempts

# Chrome Enterprise Policy - Restrict extension installations
# Add to Chrome policy configuration (Windows Registry or managed preferences on macOS/Linux)

# Block all extensions except explicitly allowed ones
ExtensionInstallBlocklist: "*"

# Allow only specific trusted extensions by ID
ExtensionInstallAllowlist: ["extension_id_1", "extension_id_2"]

# Restrict extension sources to Chrome Web Store only
ExtensionInstallSources: []