CVE-2023-4762: Google Chrome V8 Type Confusion RCE Flaw

CVE-2023-4762 Overview

CVE-2023-4762 is a type confusion vulnerability in the V8 JavaScript engine used by Google Chrome prior to version 116.0.5845.179. This vulnerability allows a remote attacker to execute arbitrary code by enticing a victim to visit a specially crafted HTML page. The flaw has been confirmed as actively exploited in the wild and has been added to CISA's Known Exploited Vulnerabilities (KEV) catalog.

Critical Impact

This vulnerability enables remote code execution through malicious web content, allowing attackers to potentially gain full control of affected systems. Due to confirmed active exploitation, immediate patching is essential.

Affected Products

• Google Chrome (versions prior to 116.0.5845.179)
• Microsoft Edge Chromium (Chromium-based versions)
• Debian Linux 11.0 and 12.0
• Fedora 37, 38, and 39

Discovery Timeline

• September 5, 2023 - CVE-2023-4762 published to NVD
• October 24, 2025 - Last updated in NVD database

Technical Details for CVE-2023-4762

Vulnerability Analysis

This type confusion vulnerability (CWE-843) resides in Chrome's V8 JavaScript engine, which is responsible for parsing and executing JavaScript code in the browser. Type confusion occurs when code allocates or initializes an object of one type but later accesses the same memory location using an incompatible type pointer. In the context of V8, this can lead to memory corruption when the JavaScript engine incorrectly handles object types during runtime optimization.

The vulnerability requires user interaction—specifically, the victim must navigate to a malicious webpage containing crafted JavaScript. Once triggered, the type confusion can corrupt memory in a predictable way, allowing an attacker to hijack program execution flow and achieve arbitrary code execution within the context of the browser process.

Root Cause

The root cause is improper type handling within V8's Just-In-Time (JIT) compilation and optimization pipeline. When V8 optimizes JavaScript code for performance, it makes assumptions about object types. If these assumptions are violated through carefully crafted JavaScript that causes the engine to misinterpret an object's actual type, memory corruption occurs. The type mismatch allows attackers to read or write memory at unintended locations, ultimately enabling code execution.

Attack Vector

The attack is delivered remotely over the network and requires user interaction. An attacker must convince a victim to visit a malicious website or click a link that leads to attacker-controlled content. The attack sequence typically involves:

1. Attacker hosts a malicious webpage containing JavaScript that triggers the type confusion
2. Victim navigates to the malicious page (via phishing, malicious ads, or compromised legitimate sites)
3. V8 engine processes the malicious JavaScript, triggering the type confusion
4. Memory corruption enables the attacker to execute arbitrary code
5. Attacker gains code execution within the browser's renderer process, potentially escaping the sandbox through additional exploits

The vulnerability affects all Chromium-based browsers, including Google Chrome and Microsoft Edge, making it particularly impactful given their combined market share.

Detection Methods for CVE-2023-4762

Indicators of Compromise

• Unexpected browser crashes or instability, particularly when visiting unfamiliar websites
• Anomalous network connections from browser processes to suspicious external hosts
• Unusual child processes spawned by Chrome or Edge browser processes
• Memory allocation anomalies or access violations logged in system event logs

Detection Strategies

• Monitor browser version deployment across endpoints and flag any installations running Chrome versions prior to 116.0.5845.179
• Implement web content filtering to block access to known malicious domains serving exploit code
• Deploy endpoint detection and response (EDR) solutions capable of detecting memory corruption exploitation techniques
• Analyze browser crash reports for patterns consistent with type confusion exploitation

Monitoring Recommendations

• Enable enhanced JavaScript logging in enterprise browser deployments to identify suspicious script behavior
• Monitor for unusual process creation events originating from browser processes
• Configure SIEM rules to alert on browser processes exhibiting code execution behaviors outside normal patterns
• Establish baseline browser behavior and alert on deviations indicative of exploitation

How to Mitigate CVE-2023-4762

Immediate Actions Required

• Update Google Chrome to version 116.0.5845.179 or later immediately
• Update Microsoft Edge Chromium to the latest patched version
• Apply distribution-specific security updates for Debian and Fedora systems running Chromium
• Prioritize patching given confirmed active exploitation and CISA KEV listing

Patch Information

Google has released Chrome version 116.0.5845.179 which addresses this vulnerability. For detailed patch information, refer to the Google Chrome Update Announcement. Microsoft has also released corresponding patches for Edge Chromium, documented in the Microsoft Security Advisory.

Linux distributions have released security updates:

• Debian users should apply DSA-5491
• Fedora users should apply updates per the Fedora Security Announcements
• Gentoo users should reference GLSA 202311-11

Workarounds

• Consider disabling JavaScript in Chrome via chrome://settings/content/javascript for high-risk users until patching is complete (note: this significantly impacts browsing functionality)
• Implement network-level blocking of known malicious domains serving exploits
• Use browser isolation technologies to contain potential exploitation attempts
• Restrict access to untrusted websites through web filtering solutions

# Verify Chrome version on Linux systems
google-chrome --version
# Expected output should be 116.0.5845.179 or later

# Check for available updates on Debian/Ubuntu
sudo apt update && sudo apt list --upgradable | grep -i chromium

# Check for available updates on Fedora
sudo dnf check-update chromium