CVE-2023-5996: Google Chrome Use After Free Vulnerability

CVE-2023-5996 Overview

CVE-2023-5996 is a use-after-free vulnerability in the WebAudio component of Google Chrome. This memory corruption flaw exists in Chrome versions prior to 119.0.6045.123 and allows a remote attacker to potentially exploit heap corruption through a specially crafted HTML page. The vulnerability is classified with Chromium security severity as High.

Critical Impact

Remote attackers can exploit this use-after-free condition to achieve heap corruption, potentially leading to arbitrary code execution within the browser context when a user visits a malicious webpage.

Affected Products

• Google Chrome versions prior to 119.0.6045.123
• Debian Linux 11.0 and 12.0
• Fedora 38 and 39

Discovery Timeline

• 2023-11-08 - CVE-2023-5996 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-5996

Vulnerability Analysis

This use-after-free vulnerability (CWE-416) resides in Chrome's WebAudio API implementation. Use-after-free conditions occur when a program continues to reference memory after it has been freed, potentially allowing an attacker to manipulate the freed memory region before the dangling pointer is dereferenced.

In the context of WebAudio, this component handles complex audio processing operations including audio graph manipulation, real-time audio synthesis, and audio node management. The vulnerability allows for heap corruption when processing maliciously crafted audio content embedded within an HTML page. Successful exploitation requires user interaction—specifically, the victim must navigate to an attacker-controlled webpage containing the malicious payload.

The network-based attack vector combined with the low complexity of exploitation makes this vulnerability particularly concerning for enterprise environments where users may inadvertently visit compromised websites.

Root Cause

The root cause stems from improper memory lifecycle management within the WebAudio component. When audio resources are deallocated, certain references to those memory regions are not properly invalidated, creating dangling pointers. Subsequent operations on these invalid references lead to the use-after-free condition, allowing attackers to corrupt heap memory structures.

Attack Vector

The attack is delivered remotely via a network vector, requiring a victim to interact with a malicious HTML page. An attacker would craft a webpage containing specialized JavaScript code that manipulates the WebAudio API in a manner that triggers the use-after-free condition. The attack flow typically involves:

1. The victim visits a malicious or compromised website
2. The attacker's JavaScript code creates and manipulates WebAudio objects in a specific sequence
3. Memory is freed while references still exist
4. The dangling reference is dereferenced, causing heap corruption
5. Depending on heap state, the attacker may achieve code execution

The vulnerability mechanism exploits the timing and ordering of WebAudio object creation, manipulation, and destruction. For detailed technical analysis, refer to Chrome Bug Report #1497859 and the Google Chrome Update Notice.

Detection Methods for CVE-2023-5996

Indicators of Compromise

• Unusual browser crashes or instability when visiting specific websites
• Unexpected memory consumption patterns in Chrome processes
• Detection of exploit kit traffic targeting Chrome vulnerabilities
• Browser process spawning unexpected child processes or network connections

Detection Strategies

• Monitor for Chrome versions below 119.0.6045.123 across the enterprise using software inventory tools
• Deploy endpoint detection and response (EDR) solutions capable of detecting heap corruption attacks
• Implement web filtering to block known malicious domains distributing browser exploits
• Enable browser crash reporting and analyze crash dumps for signs of exploitation attempts

Monitoring Recommendations

• Configure SentinelOne agents to monitor for anomalous browser process behavior
• Enable Chrome's built-in security features including Safe Browsing and Site Isolation
• Implement network monitoring for connections to suspicious domains following browser exploit patterns
• Review endpoint telemetry for unusual JavaScript execution patterns in browser contexts

How to Mitigate CVE-2023-5996

Immediate Actions Required

• Update Google Chrome to version 119.0.6045.123 or later immediately
• Apply security updates from Debian (DSA-5551) and Fedora package repositories
• Enable automatic updates for Chrome to ensure timely patching of future vulnerabilities
• Consider temporary restrictions on WebAudio API usage via enterprise policies if patching is delayed

Patch Information

Google has released Chrome version 119.0.6045.123 which addresses this vulnerability. The fix is included in the stable channel update released in November 2023. Linux distributions have also released corresponding security updates:

• Debian: Security Advisory DSA-5551
• Fedora: Available via Fedora Package Announcement
• Gentoo: GLSA 202311-11, GLSA 202312-07, and GLSA 202401-34

Workarounds

• Use an alternative browser temporarily until Chrome can be updated
• Implement content security policies to restrict untrusted JavaScript execution
• Deploy browser isolation solutions to contain potential exploitation attempts
• Block access to untrusted websites using web proxies or DNS filtering

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

# Update Chrome on Debian/Ubuntu
sudo apt update && sudo apt upgrade google-chrome-stable

# Update Chrome on Fedora
sudo dnf update chromium