CVE-2024-7973
📋 TL;DR
A heap buffer overflow vulnerability in Chrome's PDFium PDF rendering engine allows remote attackers to perform out-of-bounds memory reads via malicious PDF files. This affects all Chrome users who open PDF files, potentially leading to information disclosure or as a stepping stone for further exploitation. The vulnerability is present in Chrome versions prior to 128.0.6613.84.
💻 Affected Systems
- Google Chrome
- Chromium-based browsers
📦 What is this software?
Chrome by Google
Google Chrome is the world's most popular web browser, used by over 3 billion users globally across Windows, macOS, Linux, Android, and iOS platforms. As a Chromium-based browser developed by Google, Chrome dominates the browser market with approximately 65% market share, making it a critical compon...
Learn more about Chrome →⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or ransomware deployment through memory corruption chained with other vulnerabilities.
Likely Case
Information disclosure through memory reads, application crashes (denial of service), or limited data exfiltration from browser memory.
If Mitigated
No impact if Chrome is fully patched or if PDF files are handled by external applications instead of Chrome's built-in viewer.
🎯 Exploit Status
Exploitation requires user interaction (opening a malicious PDF). No public exploit code is known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 128.0.6613.84 and later
Vendor Advisory: https://chromereleases.googleblog.com/2024/08/stable-channel-update-for-desktop_21.html
Restart Required: Yes
Instructions:
1. Open Chrome. 2. Click the three-dot menu → Help → About Google Chrome. 3. Chrome will automatically check for and install updates. 4. Click 'Relaunch' to restart Chrome with the patched version.
🔧 Temporary Workarounds
Disable Chrome PDF Viewer
allConfigure Chrome to use external PDF applications instead of its built-in PDFium viewer.
chrome://settings/content/pdfDocuments → Toggle 'Download PDF files instead of automatically opening them in Chrome' to ON
Block PDF Downloads via Policy
allUse group policy or management tools to block PDF file downloads in Chrome.
Set 'DefaultDownloadSecurity' policy to block PDF files
🧯 If You Can't Patch
- Use alternative browsers without PDF rendering capabilities for PDF handling
- Implement application whitelisting to block Chrome execution in high-risk environments
🔍 How to Verify
Check if Vulnerable:
Check Chrome version: If version is below 128.0.6613.84, the system is vulnerable.Check Version:
chrome://version/Verify Fix Applied:
Confirm Chrome version is 128.0.6613.84 or higher after update.📡 Detection & Monitoring
Log Indicators:
- Chrome crash logs with PDF-related stack traces
- Security event logs showing PDF file access from untrusted sources
Network Indicators:
- Unusual PDF downloads from external sources
- PDF files with abnormal file sizes or structures
SIEM Query:
source="chrome_logs" AND (event="crash" AND process="chrome" AND module="pdfium") OR (file_type="pdf" AND source_ip="external")