CVE-2023-3727: Google Chrome Use After Free Vulnerability

CVE-2023-3727 Overview

CVE-2023-3727 is a Use After Free vulnerability affecting the WebRTC component in Google Chrome prior to version 115.0.5790.98. 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 the Chromium security team due to its potential for significant impact.

Critical Impact

Remote attackers can exploit this use-after-free vulnerability through malicious web pages to corrupt heap memory, potentially leading to arbitrary code execution in the context of the browser process.

Affected Products

• Google Chrome versions prior to 115.0.5790.98
• Chromium-based browsers incorporating vulnerable WebRTC components
• Linux distributions shipping affected Chrome/Chromium packages (Fedora, Gentoo)

Discovery Timeline

• 2023-08-01 - CVE-2023-3727 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-3727

Vulnerability Analysis

This vulnerability is classified as CWE-416 (Use After Free), a memory corruption issue that occurs when a program continues to use a pointer after the memory it references has been freed. In the context of WebRTC within Google Chrome, this creates a dangerous condition where an attacker can manipulate the freed memory region before the stale pointer is dereferenced.

The WebRTC (Web Real-Time Communication) component handles complex real-time audio, video, and data communication functionality. The intricate memory management required for these operations creates opportunities for use-after-free conditions when object lifetimes are not properly managed. When triggered via a specially crafted HTML page, this vulnerability can lead to heap corruption.

The attack requires user interaction (visiting a malicious page) but can be executed remotely over the network without authentication. A successful exploit could allow an attacker to achieve arbitrary code execution within the Chrome sandbox, potentially leading to information disclosure, data manipulation, or further system compromise depending on sandbox escape capabilities.

Root Cause

The vulnerability stems from improper memory lifecycle management within the WebRTC implementation. When certain WebRTC objects are deallocated, references to that memory are not properly invalidated, leaving dangling pointers that can be subsequently accessed. This use-after-free condition allows attackers to control the contents of the freed memory region through heap manipulation techniques, potentially redirecting program execution flow.

Attack Vector

The attack is delivered through a network-based vector requiring the victim to navigate to a malicious HTML page. The crafted page contains JavaScript that manipulates WebRTC API calls in a specific sequence to trigger the use-after-free condition. Once the vulnerability is triggered, the attacker can corrupt heap memory structures.

The exploitation flow typically involves:

1. Allocating WebRTC objects through legitimate API calls
2. Triggering the deallocation of specific objects while maintaining stale references
3. Spraying the heap with attacker-controlled data to occupy the freed memory
4. Accessing the stale pointer to achieve controlled memory corruption

Exploitation details are tracked in the Google Chrome Bug Report.

Detection Methods for CVE-2023-3727

Indicators of Compromise

• Unusual Chrome/Chromium process crashes with heap corruption signatures
• Browser processes exhibiting unexpected memory access patterns during WebRTC sessions
• Security event logs indicating heap corruption or access violations in browser processes
• Anomalous WebRTC API call sequences observed in web traffic analysis

Detection Strategies

• Monitor for Chrome versions below 115.0.5790.98 in enterprise asset inventory
• Deploy endpoint detection solutions capable of identifying heap spray and use-after-free exploitation patterns
• Implement browser isolation for untrusted web content to contain potential exploitation
• Configure web proxies to log and analyze WebRTC-related traffic patterns

Monitoring Recommendations

• Enable Chrome crash reporting and analyze crash dumps for heap corruption indicators
• Deploy SentinelOne Singularity platform for real-time detection of memory corruption exploitation attempts
• Monitor for abnormal child process creation from Chrome browser processes
• Implement network traffic analysis to identify suspicious HTML/JavaScript payloads targeting WebRTC

How to Mitigate CVE-2023-3727

Immediate Actions Required

• Update Google Chrome to version 115.0.5790.98 or later immediately
• Enable automatic Chrome updates to ensure timely security patches
• Consider temporarily disabling WebRTC functionality in high-risk environments using browser policies
• Deploy SentinelOne endpoint protection to detect and block exploitation attempts

Patch Information

Google addressed this vulnerability in the Chrome 115.0.5790.98 stable channel release. The fix properly manages WebRTC object lifetimes to prevent the use-after-free condition. Organizations should consult the Google Chrome Stable Update for complete release notes.

Linux distribution users should apply updates through their package managers. Fedora users can reference the Fedora Package Announcement and Gentoo users should consult Gentoo GLSA Advisory 202401-34.

Workarounds

• Implement browser isolation solutions to contain potential exploitation in sandboxed environments
• Use enterprise browser policies to restrict WebRTC functionality if not business-critical
• Deploy network-level filtering to block known malicious domains serving exploit payloads
• Consider using alternative browsers temporarily while Chrome updates are deployed across the organization

# Chrome Enterprise Policy - Disable WebRTC (Windows Registry)
# HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome
# Create DWORD: WebRtcLocalIpsAllowedUrls with value restricting allowed origins

# Linux: Verify Chrome version
google-chrome --version
# Expected: Google Chrome 115.0.5790.98 or higher

# Force Chrome update check
google-chrome --check-for-update-interval=0