CVE-2023-0472: Google Chrome Use After Free Vulnerability

CVE-2023-0472 Overview

CVE-2023-0472 is a Use After Free vulnerability in the WebRTC component of Google Chrome prior to version 109.0.5414.119. This memory corruption flaw allows a remote attacker to potentially exploit heap corruption via a crafted HTML page. The vulnerability was assigned a high severity rating by Chromium security.

Critical Impact

Remote attackers can exploit this vulnerability to achieve heap corruption through malicious web pages, potentially leading to arbitrary code execution within the browser context.

Affected Products

• Google Chrome versions prior to 109.0.5414.119
• Chromium-based browsers using vulnerable WebRTC implementations

Discovery Timeline

• 2023-01-30 - CVE-2023-0472 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-0472

Vulnerability Analysis

This vulnerability is classified as CWE-416 (Use After Free), a type of memory corruption vulnerability that occurs when a program continues to use a pointer after it has been freed. In the context of WebRTC within Google Chrome, this flaw allows attackers to reference memory that has already been deallocated.

When successfully exploited, this vulnerability can lead to heap corruption. An attacker can craft a malicious HTML page that triggers the use-after-free condition in the WebRTC component. Since WebRTC handles real-time communication features including audio, video, and data sharing, the component has significant access to system resources, making this vulnerability particularly dangerous.

The attack requires user interaction—the victim must navigate to a malicious web page. However, once triggered, the vulnerability could allow an attacker to execute arbitrary code within the context of the browser process, potentially compromising user data, session information, and in worst-case scenarios, achieving broader system compromise.

Root Cause

The root cause of CVE-2023-0472 lies in improper memory management within Chrome's WebRTC implementation. Specifically, the vulnerability occurs when memory is freed but pointers to that memory are not properly invalidated or nullified. Subsequent operations that reference this freed memory can then lead to heap corruption.

Use-after-free vulnerabilities in browser components are particularly dangerous because browsers operate in complex, multi-threaded environments where timing issues can exacerbate memory management problems. In WebRTC specifically, the handling of media streams and peer connections involves numerous objects with complex lifecycles that must be carefully managed.

Attack Vector

The attack vector for CVE-2023-0472 is network-based, requiring user interaction with a maliciously crafted web page. The exploitation scenario follows this pattern:

1. An attacker creates a specially crafted HTML page containing malicious WebRTC code
2. The victim is lured to visit this page through phishing, malvertising, or compromised legitimate websites
3. The malicious page triggers the use-after-free condition in Chrome's WebRTC component
4. Upon successful exploitation, heap corruption occurs, potentially allowing code execution

The vulnerability is particularly concerning because it requires no special privileges or authentication—only that a user visits a malicious website with a vulnerable Chrome version. Technical details of the vulnerability can be found in the Chromium Bug Report #1405256.

Detection Methods for CVE-2023-0472

Indicators of Compromise

• Unexpected Chrome browser crashes or instability, particularly when accessing WebRTC-enabled websites
• Suspicious network connections initiated from the browser process following visits to unknown websites
• Memory access violations or heap corruption errors logged in system crash dumps
• Unusual child processes spawned by the Chrome browser process

Detection Strategies

• Monitor browser version inventories across endpoints to identify instances running Chrome versions prior to 109.0.5414.119
• Deploy endpoint detection rules that identify suspicious WebRTC-related memory access patterns
• Implement web proxy logging to detect access to known malicious domains distributing exploits
• Utilize browser telemetry to identify abnormal WebRTC component behavior

Monitoring Recommendations

• Enable enhanced crash reporting in Chrome deployments to capture detailed information about potential exploitation attempts
• Configure endpoint detection and response (EDR) solutions to monitor Chrome process behavior for signs of heap corruption exploitation
• Implement network monitoring for unusual outbound connections following WebRTC activity
• Review browser extension installations that could potentially trigger or amplify WebRTC vulnerabilities

How to Mitigate CVE-2023-0472

Immediate Actions Required

• Update Google Chrome to version 109.0.5414.119 or later immediately across all endpoints
• Enable automatic updates for Chrome browsers to ensure timely patching of future vulnerabilities
• Consider using enterprise Chrome management tools to enforce version requirements
• Educate users about the risks of visiting untrusted websites

Patch Information

Google has addressed this vulnerability in Chrome version 109.0.5414.119, released on January 24, 2023. The patch corrects the memory management issue in the WebRTC component that allowed the use-after-free condition. Organizations should update to this version or later to remediate the vulnerability.

For detailed patch information, refer to the Google Chrome Stable Channel Update Announcement.

Workarounds

• If immediate patching is not possible, consider disabling WebRTC functionality in Chrome through browser policies or extensions as a temporary measure
• Implement strict browsing policies that limit access to untrusted websites
• Deploy web filtering solutions to block known malicious domains
• Use browser isolation technologies to contain potential exploitation attempts

# Chrome Enterprise Policy Configuration to disable WebRTC (temporary workaround)
# Add to Chrome policy template or group policy

# Windows Registry approach:
# HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome
# Create DWORD: WebRtcAllowLegacyTLSProtocols = 0

# Linux/macOS managed preferences:
# Set WebRtcIPHandlingPolicy to "disable_non_proxied_udp" to limit WebRTC exposure