CVE-2024-6291: Google Chrome Use After Free Vulnerability

CVE-2024-6291 Overview

CVE-2024-6291 is a use-after-free vulnerability in Swiftshader, a software-based GPU implementation used by Google Chrome for WebGL rendering when hardware acceleration is unavailable. This vulnerability affects Google Chrome versions prior to 126.0.6478.126 and allows a remote attacker to potentially exploit heap corruption via a crafted HTML page. The vulnerability has been classified with High severity by the Chromium security team.

Critical Impact

Remote attackers can exploit this heap corruption vulnerability through malicious web pages, potentially achieving arbitrary code execution in the context of the Chrome browser process.

Affected Products

• Google Chrome versions prior to 126.0.6478.126
• Fedora Project Fedora 39
• Fedora Project Fedora 40

Discovery Timeline

• June 24, 2024 - CVE-2024-6291 published to NVD
• December 26, 2024 - Last updated in NVD database

Technical Details for CVE-2024-6291

Vulnerability Analysis

This vulnerability is a use-after-free (CWE-416) memory corruption flaw in Chrome's Swiftshader component. Swiftshader is Google's software-based implementation of the Vulkan and OpenGL ES graphics APIs, providing CPU-based graphics rendering when GPU hardware acceleration is unavailable or disabled. The vulnerability occurs when Swiftshader improperly handles memory during graphics operations, resulting in a condition where memory is accessed after being freed.

Use-after-free vulnerabilities in browser rendering components are particularly dangerous because they can be triggered simply by visiting a malicious website. The attack requires user interaction (visiting a malicious page), but no other privileges or authentication are needed. Successful exploitation could result in complete compromise of confidentiality, integrity, and availability of the affected system.

Root Cause

The root cause of CVE-2024-6291 stems from improper memory lifecycle management in the Swiftshader graphics rendering engine. When certain graphics objects are deallocated, references to these freed memory regions may persist. Subsequent operations that attempt to use these stale references result in use-after-free conditions. The freed memory can be reallocated for other purposes, and when the dangling reference is dereferenced, it may access attacker-controlled data, leading to heap corruption that can be leveraged for code execution.

Attack Vector

The attack vector for CVE-2024-6291 is network-based, requiring the victim to navigate to a malicious web page containing specially crafted HTML and JavaScript code. The attacker must construct a page that triggers the vulnerable code path in Swiftshader, typically through WebGL or other graphics APIs that utilize the software renderer. When the victim visits the malicious page, the crafted content triggers the use-after-free condition, corrupting the heap and potentially allowing arbitrary code execution within the browser sandbox.

The vulnerability mechanism involves triggering specific Swiftshader rendering operations that expose the memory management flaw. Attackers would craft WebGL shaders or rendering commands that manipulate object lifetimes to create a race condition or sequence of operations resulting in use-after-free access. For detailed technical information, see the Chromium Issue Tracker Entry.

Detection Methods for CVE-2024-6291

Indicators of Compromise

• Unusual Chrome browser crashes or instability when rendering WebGL content
• Unexpected memory access violations or heap corruption errors in Chrome crash reports
• Presence of suspicious HTML pages containing complex WebGL shader code designed to trigger rendering edge cases
• Browser process spawning unexpected child processes or network connections after visiting untrusted websites

Detection Strategies

• Monitor for Chrome versions below 126.0.6478.126 across enterprise endpoints using asset management tools
• Implement browser version enforcement policies to ensure timely updates
• Deploy endpoint detection and response (EDR) solutions capable of detecting memory corruption exploitation attempts
• Enable Chrome's crash reporting and analyze crash dumps for patterns consistent with use-after-free exploitation

Monitoring Recommendations

• Configure centralized logging for browser crashes and anomalies across the enterprise
• Establish alerts for Chrome processes exhibiting unusual memory access patterns or heap corruption indicators
• Monitor network traffic for indicators of drive-by download attacks targeting browser vulnerabilities
• Regularly audit browser versions deployed across the organization to identify vulnerable installations

How to Mitigate CVE-2024-6291

Immediate Actions Required

• Update Google Chrome to version 126.0.6478.126 or later immediately across all systems
• Enable automatic Chrome updates if not already configured to ensure timely patching
• Review Chrome's software renderer usage policy and consider disabling Swiftshader if hardware acceleration is available
• Implement web filtering to block access to known malicious domains serving browser exploits

Patch Information

Google has addressed this vulnerability in Chrome version 126.0.6478.126. The fix was announced in the Google Chrome Stable Channel Update released on June 24, 2024. Fedora users should apply the relevant security updates for Fedora 39 and Fedora 40 as detailed in the Fedora package announcements. Organizations should prioritize immediate deployment of this update to all Chrome installations.

Workarounds

• Disable Chrome's software rendering (Swiftshader) by using the --disable-software-rasterizer command-line flag, though this may impact functionality on systems without GPU support
• Implement strict content security policies to limit WebGL usage on untrusted websites
• Use browser isolation solutions to contain potential exploitation attempts from web-based threats
• Consider deploying network-level protections to filter malicious web content before it reaches endpoints

# Force Chrome update via command line (Windows)
# Run Chrome with update flags
"C:\Program Files\Google\Chrome\Application\chrome.exe" --check-for-update

# Disable software rasterizer as a temporary workaround (Linux/macOS)
google-chrome --disable-software-rasterizer

# Verify Chrome version
google-chrome --version