CVE-2023-3420: Google Chrome V8 Type Confusion RCE Flaw

CVE-2023-3420 Overview

CVE-2023-3420 is a type confusion vulnerability in the V8 JavaScript engine used by Google Chrome versions prior to 114.0.5735.198. This vulnerability allows a remote attacker to potentially exploit heap corruption through a crafted HTML page, enabling arbitrary code execution within the context of the browser process.

Critical Impact

Remote attackers can exploit this type confusion flaw in V8 to achieve heap corruption, potentially leading to arbitrary code execution when victims visit malicious websites.

Affected Products

• Google Chrome versions prior to 114.0.5735.198
• Debian Linux 11.0
• Debian Linux 12.0

Discovery Timeline

• 2023-06-26 - CVE-2023-3420 published to NVD
• 2025-05-05 - Last updated in NVD database

Technical Details for CVE-2023-3420

Vulnerability Analysis

This vulnerability is a type confusion issue (CWE-843) residing in Chrome's V8 JavaScript engine. Type confusion occurs when code doesn't verify the type of an object before using it, leading to out-of-bounds memory access or other memory safety violations. In this case, V8 mishandles object types during JavaScript execution, which can be triggered by specially crafted JavaScript embedded in an HTML page.

The exploitation requires user interaction—specifically, a victim must navigate to a malicious webpage containing the crafted HTML and JavaScript. Once triggered, the type confusion enables heap corruption, which sophisticated attackers can leverage for arbitrary code execution within the browser's renderer process.

Root Cause

The root cause stems from improper type handling within V8's JavaScript engine. When V8 processes certain JavaScript operations, it may incorrectly assume the type of an object, leading to memory operations being performed on mismatched data structures. This type confusion creates opportunities for heap corruption when the engine attempts to access or manipulate memory based on incorrect type assumptions.

Attack Vector

The attack vector is network-based and requires user interaction. An attacker would need to:

1. Create a malicious HTML page containing crafted JavaScript code designed to trigger the type confusion
2. Lure a victim to visit the malicious page through phishing, malvertising, or compromising a legitimate website
3. When the victim's browser loads and executes the malicious JavaScript, the type confusion triggers heap corruption
4. The attacker can then potentially achieve arbitrary code execution within the browser context

The vulnerability is particularly dangerous because it can be exploited remotely through any website the victim visits, making it suitable for drive-by download attacks and watering hole campaigns.

Detection Methods for CVE-2023-3420

Indicators of Compromise

• Unexpected browser crashes or instability when visiting specific websites
• V8 engine errors or exceptions in browser debugging console logs
• Anomalous JavaScript execution patterns detected by endpoint protection
• Unusual memory access patterns in Chrome renderer processes

Detection Strategies

• Monitor for Chrome versions below 114.0.5735.198 across your environment using asset inventory tools
• Deploy browser-based threat detection to identify malicious JavaScript execution patterns
• Implement network monitoring to detect known malicious URLs targeting this vulnerability
• Use SentinelOne's behavioral AI to detect exploit attempts through anomalous process behavior

Monitoring Recommendations

• Enable Chrome's built-in crash reporting and review crash dumps for V8-related exceptions
• Monitor endpoint telemetry for Chrome renderer process memory anomalies
• Track browser version compliance across enterprise environments
• Review web proxy logs for access to suspicious or newly registered domains

How to Mitigate CVE-2023-3420

Immediate Actions Required

• Update Google Chrome to version 114.0.5735.198 or later immediately
• Enable automatic browser updates to ensure timely security patches
• Apply Debian security updates if running affected Debian Linux versions
• Restrict browsing on unpatched systems to trusted, business-critical sites only

Patch Information

Google has released Chrome version 114.0.5735.198 which addresses this vulnerability. Detailed information is available in the Google Chrome Update Announcement. Additional security advisories have been issued by:

• Debian Security Advisory DSA-5440
• Gentoo GLSA 202401-34
• Fedora package updates for affected distributions

Organizations should prioritize updating Chrome across all endpoints and apply corresponding updates for Chromium-based browsers and embedded Chromium components in other applications.

Workarounds

• Disable JavaScript execution in Chrome via settings for untrusted sites (impacts functionality significantly)
• Use enterprise browser policies to restrict access to untrusted web content
• Implement network-level web filtering to block access to known malicious domains
• Consider using an alternative browser temporarily on systems where immediate patching is not possible

# Verify Chrome version on Linux systems
google-chrome --version

# Force Chrome update check
google-chrome --check-for-update

# Check for available Debian security updates
sudo apt-get update && apt-cache policy chromium