CVE-2024-7536: Google Chrome Use After Free Vulnerability

CVE-2024-7536 Overview

CVE-2024-7536 is a Use After Free vulnerability in the WebAudio component of Google Chrome prior to version 127.0.6533.99. This memory corruption flaw allows a remote attacker to potentially exploit heap corruption through a specially crafted HTML page. When a user visits a malicious web page, the attacker can trigger the use-after-free condition in the WebAudio API, potentially leading to arbitrary code execution within the context of the browser process.

Critical Impact

Remote attackers can potentially achieve heap corruption and code execution by luring victims to malicious websites, compromising confidentiality, integrity, and availability of affected systems.

Affected Products

• Google Chrome versions prior to 127.0.6533.99
• All platforms running vulnerable Chrome versions (Windows, macOS, Linux)
• Chromium-based browsers that incorporate the affected WebAudio component

Discovery Timeline

• 2024-08-06 - CVE-2024-7536 published to NVD
• 2024-08-12 - Last updated in NVD database

Technical Details for CVE-2024-7536

Vulnerability Analysis

This vulnerability is classified as CWE-416 (Use After Free), a dangerous memory corruption class where the application continues to use a pointer after the memory it references has been freed. In the context of Google Chrome's WebAudio API, the flaw exists in how audio processing objects manage memory during complex audio graph operations.

The WebAudio API provides powerful audio processing capabilities for web applications, including real-time audio synthesis, analysis, and manipulation. The vulnerability allows attackers to manipulate the timing of audio node destruction and reference, creating a condition where freed memory is accessed. Since Chrome handles audio processing with privileged access to system resources, successful exploitation could allow an attacker to execute arbitrary code with the permissions of the browser process.

Root Cause

The root cause stems from improper memory lifecycle management in Chrome's WebAudio implementation. When audio nodes are connected in complex graphs and subsequently modified or destroyed, race conditions or improper reference counting can lead to a scenario where a pointer to a freed audio buffer or node object is dereferenced. The heap corruption that follows can be leveraged by attackers to gain control over program execution.

Attack Vector

The attack is network-based and requires user interaction—specifically, a victim must navigate to a malicious webpage crafted by the attacker. The attacker embeds JavaScript code that manipulates the WebAudio API in specific ways to trigger the use-after-free condition. Once triggered, the corrupted heap state can be exploited through heap spraying or other memory manipulation techniques to achieve code execution.

The vulnerability does not require any special privileges or authentication, making it accessible to any remote attacker who can convince a user to visit a malicious page. Exploitation complexity is considered low given the predictable nature of browser memory layouts and the availability of JavaScript for precise heap manipulation.

Detection Methods for CVE-2024-7536

Indicators of Compromise

• Unexpected browser crashes or hangs when visiting specific web pages
• Anomalous memory access patterns in Chrome's audio processing threads
• JavaScript errors related to AudioContext or AudioNode objects in browser console
• Unusual network requests to domains hosting exploit kits or malicious audio content

Detection Strategies

• Monitor for Chrome crash reports indicating heap corruption in WebAudio components
• Deploy browser isolation technologies to contain potential exploitation attempts
• Implement content security policies to restrict JavaScript audio API usage from untrusted sources
• Use endpoint detection tools to identify suspicious browser process behavior following web navigation

Monitoring Recommendations

• Enable Chrome's crash reporting and monitor for patterns indicating WebAudio exploitation
• Review web proxy logs for access to known exploit kit domains or suspicious JavaScript payloads
• Monitor endpoint telemetry for unusual child process creation from Chrome browser processes
• Track Chrome version deployment across the organization to identify unpatched systems

How to Mitigate CVE-2024-7536

Immediate Actions Required

• Update Google Chrome to version 127.0.6533.99 or later immediately
• Enable automatic Chrome updates to ensure timely patch deployment
• Consider disabling WebAudio API via enterprise policy for high-risk environments until patching is complete
• Implement browser isolation for users accessing untrusted web content

Patch Information

Google has addressed this vulnerability in Chrome version 127.0.6533.99. The fix was released as part of a stable channel update in August 2024. Organizations should prioritize deploying this update across all endpoints. For detailed information about the security update, refer to the Google Chrome Release Update. Technical details about the specific issue can be found in the Chromium Issue Tracker Entry.

Workarounds

• Deploy browser isolation solutions to execute untrusted web content in sandboxed environments
• Use enterprise Chrome policies to restrict access to untrusted or high-risk websites
• Consider using Chrome's Site Isolation feature to limit cross-site exploitation potential
• Implement network-level filtering to block known malicious domains serving exploit content

# Chrome Enterprise Policy to disable WebAudio API (temporary mitigation)
# Add to Chrome policies JSON configuration
{
  "AudioCaptureAllowed": false,
  "DefaultWebUsbGuardSetting": 2
}