CVE-2024-6994: Google Chrome Buffer Overflow Vulnerability

CVE-2024-6994 Overview

CVE-2024-6994 is a heap buffer overflow vulnerability in the Layout component of Google Chrome versions prior to 127.0.6533.72. A remote attacker can exploit heap corruption by serving a crafted HTML page to a victim user. The flaw is tracked under [CWE-122] (Heap-based Buffer Overflow) and [CWE-787] (Out-of-Bounds Write). Successful exploitation requires user interaction, such as visiting a malicious website. Chromium rates the security severity as Medium, while NVD assigns a CVSS 3.1 score of 8.8 (High). The EPSS score is 0.732% (73rd percentile), indicating moderate exploitation likelihood relative to other CVEs.

Critical Impact
Remote attackers can trigger heap corruption in the Chrome renderer through a crafted HTML page, enabling potential arbitrary code execution within the browser process.

Affected Products

Google Chrome versions prior to 127.0.6533.72 (Stable channel, Desktop)
Chromium-based browsers incorporating the affected Layout code
All operating systems supported by Chrome (Windows, macOS, Linux)

Discovery Timeline

2024-08-06 - CVE-2024-6994 published to NVD
2024-08-07 - Last updated in NVD database

Technical Details for CVE-2024-6994

Vulnerability Analysis

The vulnerability resides in Chrome's Layout engine, which is responsible for computing the geometry, sizing, and positioning of HTML and CSS elements during page rendering. A heap buffer overflow occurs when the Layout code writes beyond the bounds of a heap-allocated buffer while processing specially crafted markup or style combinations. Heap corruption in this context can overwrite adjacent objects, including function pointers and virtual table entries used by Blink rendering structures. Attackers leverage such corruption to achieve control-flow hijacking inside the sandboxed renderer process. Combined with a sandbox escape, this class of flaw historically leads to full remote code execution on the host.

Root Cause

The root cause is improper bounds checking in the Layout subsystem when allocating or indexing heap memory for layout objects. The condition maps to [CWE-122] and [CWE-787], where an out-of-bounds write corrupts adjacent heap metadata or object data. Full technical details remain restricted in the Chromium Issue Tracker Issue #339686368 pending broad patch adoption.

Attack Vector

Exploitation requires the victim to load attacker-controlled HTML in a vulnerable Chrome build. The attack vector is network-based with low complexity and no privileges required, but it requires user interaction such as clicking a link or loading an iframe. A crafted HTML page triggers the Layout code path that performs the out-of-bounds write. Drive-by download scenarios, malvertising, and phishing pages serve as common delivery mechanisms. See the Google Chrome Update Announcement for vendor context.

Detection Methods for CVE-2024-6994

Indicators of Compromise

Chrome renderer process crashes (chrome.exe child processes) with heap corruption signatures shortly after visiting untrusted URLs
Unexpected child processes spawned by Chrome, particularly shells or scripting interpreters
Outbound connections from Chrome renderer or helper processes to uncommon domains following page load events
Browser navigation history entries pointing to newly registered or low-reputation domains immediately preceding crashes

Detection Strategies

Inventory installed Chrome versions across endpoints and flag any build prior to 127.0.6533.72
Correlate browser crash telemetry with proxy and DNS logs to identify malicious page loads
Monitor for renderer-to-host process anomalies that indicate sandbox escape attempts following browser exploitation

Monitoring Recommendations

Enable endpoint telemetry that captures process lineage, command-line arguments, and module loads for browser processes
Forward browser crash dumps and Windows Error Reporting (WER) events to a central SIEM for triage
Track Chrome auto-update status and alert when endpoints fail to update within the patch window

How to Mitigate CVE-2024-6994

Immediate Actions Required

Update Google Chrome to version 127.0.6533.72 or later on all endpoints, including managed kiosks and developer workstations
Verify Chromium-based browsers (Edge, Brave, Opera, Vivaldi) have applied vendor updates incorporating the upstream fix
Restart browser instances after patching to ensure the updated binary is loaded
Audit enterprise policies that disable automatic updates and re-enable them where feasible

Patch Information

Google released the fix in the Chrome Stable channel update version 127.0.6533.72 for Desktop. Refer to the Google Chrome Update Announcement for the official advisory and full list of fixes shipped in the same release.

Workarounds

Restrict browsing to trusted sites using web filtering or DNS-layer controls until patching completes
Deploy enterprise policies that block execution of unsigned child processes spawned from Chrome
Use site isolation and strict sandbox configurations to limit renderer process privileges

bash

# Verify Chrome version on Linux/macOS
google-chrome --version

# Windows: query installed version via registry
reg query "HKLM\SOFTWARE\Google\Chrome\BLBeacon" /v version

# Force update check (Linux example)
sudo apt-get update && sudo apt-get install --only-upgrade google-chrome-stable