CVE-2023-4069: Google Chrome Type Confusion Vulnerability

CVE-2023-4069 Overview

CVE-2023-4069 is a Type Confusion vulnerability in the V8 JavaScript engine used by Google Chrome prior to version 115.0.5790.170. This vulnerability allows a remote attacker to potentially exploit heap corruption via a crafted HTML page, enabling arbitrary code execution in the context of the browser. The flaw is classified under CWE-843 (Access of Resource Using Incompatible Type).

Critical Impact

A remote attacker can exploit this type confusion vulnerability to achieve heap corruption, potentially leading to arbitrary code execution. Users visiting a malicious webpage could have their systems compromised without additional interaction beyond navigating to the attacker-controlled page.

Affected Products

• Google Chrome versions prior to 115.0.5790.170
• Chromium-based browsers using affected V8 engine versions
• Fedora, Debian, and Gentoo packages containing vulnerable Chrome/Chromium versions

Discovery Timeline

• August 3, 2023 - CVE-2023-4069 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2023-4069

Vulnerability Analysis

This vulnerability is a type confusion issue within V8, Google Chrome's open-source JavaScript and WebAssembly engine. Type confusion vulnerabilities occur when code does not verify the type of an object before using it, allowing an attacker to supply an object of an incompatible type. In the context of V8, this can lead to memory corruption when the engine incorrectly interprets memory contents, treating data of one type as another.

The vulnerability can be triggered remotely by luring a victim to a specially crafted HTML page containing malicious JavaScript code. When the V8 engine processes this code, the type confusion leads to heap corruption, which can be leveraged by an attacker to achieve arbitrary code execution within the Chrome renderer process sandbox. While Chrome's sandbox provides some mitigation, successful exploitation could still lead to information disclosure, denial of service, or potentially full system compromise when combined with a sandbox escape.

Root Cause

The root cause of CVE-2023-4069 lies in the V8 JavaScript engine's handling of object types during runtime execution. Type confusion occurs when the engine fails to properly validate the type of an object before performing operations on it. This allows an attacker to craft JavaScript that causes V8 to misinterpret the structure of objects in memory, leading to out-of-bounds memory access and heap corruption.

V8's Just-In-Time (JIT) compilation and optimization processes can introduce complexity that makes type handling particularly sensitive to such issues. The compiler's assumptions about object types may not hold true in all execution paths, creating opportunities for type confusion when those assumptions are violated by carefully crafted input.

Attack Vector

The attack vector for CVE-2023-4069 is network-based and requires user interaction. An attacker must convince a user to visit a malicious webpage containing specially crafted JavaScript code. The attack flow is as follows:

1. The attacker creates a malicious HTML page with JavaScript designed to trigger the type confusion in V8
2. The victim is lured to the malicious page through phishing, malvertising, or compromised legitimate websites
3. Chrome's V8 engine processes the malicious JavaScript
4. The type confusion causes heap corruption within the renderer process
5. The attacker exploits the corrupted memory state to achieve code execution

The vulnerability manifests in V8's type handling mechanisms when processing specially crafted JavaScript. For detailed technical analysis, refer to the Chromium Bug Report and the Google Chrome Update Announcement.

Detection Methods for CVE-2023-4069

Indicators of Compromise

• Unusual memory consumption or crashes in Chrome/Chromium processes
• Browser crashes with heap corruption signatures in crash dumps
• Suspicious JavaScript execution patterns in browser process monitoring
• Unexpected child processes spawned from Chrome renderer processes

Detection Strategies

• Monitor Chrome browser version across enterprise endpoints to identify unpatched instances
• Implement browser process behavior monitoring to detect anomalous JavaScript execution patterns
• Deploy endpoint detection and response (EDR) solutions capable of identifying heap spray and type confusion exploitation techniques
• Utilize network security monitoring to identify traffic to known malicious domains serving exploit code

Monitoring Recommendations

• Configure centralized logging for Chrome crash reports to identify potential exploitation attempts
• Enable Chrome's Safe Browsing feature and monitor for blocked malicious page attempts
• Implement SentinelOne Singularity platform for real-time detection of browser-based exploitation attempts
• Monitor for suspicious memory allocation patterns associated with heap corruption attacks

How to Mitigate CVE-2023-4069

Immediate Actions Required

• Update Google Chrome to version 115.0.5790.170 or later immediately
• Enable automatic Chrome updates to ensure timely security patch deployment
• Review and update any Chromium-based applications or embedded browsers in your environment
• Consider implementing browser isolation solutions for high-risk users

Patch Information

Google has addressed this vulnerability in Chrome version 115.0.5790.170. The fix was announced in the Google Chrome Stable Channel Update in August 2023. Linux distribution vendors have also released patches:

• Debian Security Advisory DSA-5467
• Fedora Package Announcement
• Gentoo GLSA 202311-11
• Gentoo GLSA 202312-07
• Gentoo GLSA 202401-34

Workarounds

• Restrict access to untrusted websites through web filtering or proxy solutions
• Implement browser isolation technologies to contain potential exploitation
• Disable JavaScript execution for untrusted sites using browser security settings or extensions
• Deploy network-level controls to block access to known malicious domains

# Verify Chrome version on Linux systems
google-chrome --version
# Expected output should show 115.0.5790.170 or higher

# Force Chrome update on enterprise systems (example for Debian/Ubuntu)
sudo apt update && sudo apt upgrade google-chrome-stable