CVE-2021-37983
📋 TL;DR
This is a use-after-free vulnerability in Chrome's Dev Tools that allows remote attackers to potentially exploit heap corruption. Attackers can craft malicious HTML pages to trigger memory corruption, potentially leading to arbitrary code execution. All users running Chrome versions prior to 95.0.4638.54 are affected.
💻 Affected Systems
- Google Chrome
📦 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 with the same privileges as the Chrome process, potentially leading to full system compromise if Chrome is running with elevated privileges.
Likely Case
Browser crash (denial of service) or limited information disclosure through memory corruption.
If Mitigated
No impact if Chrome is fully patched or if Dev Tools are disabled/unavailable.
🎯 Exploit Status
Exploitation requires user interaction (visiting a malicious page) and knowledge of Dev Tools internals.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 95.0.4638.54
Vendor Advisory: https://chromereleases.googleblog.com/2021/10/stable-channel-update-for-desktop_19.html
Restart Required: Yes
Instructions:
1. Open Chrome. 2. Click the three-dot menu. 3. Go to Help > About Google Chrome. 4. Chrome will automatically check for and apply updates. 5. Restart Chrome when prompted.
🔧 Temporary Workarounds
Disable Dev Tools
allPrevent access to Chrome Dev Tools which contains the vulnerable component
chrome://flags/#enable-devtools-experiments (set to Disabled)
Group Policy: DeveloperToolsAvailability = 2 (Disallowed)
Disable JavaScript
allPrevent malicious HTML pages from executing JavaScript that could trigger the vulnerability
chrome://settings/content/javascript (set to Blocked)
🧯 If You Can't Patch
- Use browser isolation technology to render web content in isolated containers
- Implement strict web filtering to block access to untrusted websites
🔍 How to Verify
Check if Vulnerable:
Check Chrome version in chrome://settings/help or via 'chrome://version/'Check Version:
google-chrome --version (Linux), 'Get-AppxPackage Microsoft.WindowsStore | Select Version' (Windows Store), or check in Chrome settingsVerify Fix Applied:
Confirm Chrome version is 95.0.4638.54 or later📡 Detection & Monitoring
Log Indicators:
- Chrome crash reports with memory corruption signatures
- Unexpected Dev Tools process termination
Network Indicators:
- Requests to known malicious domains hosting exploit code
- Unusual Dev Tools protocol traffic
SIEM Query:
source="chrome_crash_reports" AND (event_id="1001" OR memory_corruption="true")🔗 References
- https://chromereleases.googleblog.com/2021/10/stable-channel-update-for-desktop_19.html
- https://crbug.com/1249810
- https://www.debian.org/security/2022/dsa-5046
- https://chromereleases.googleblog.com/2021/10/stable-channel-update-for-desktop_19.html
- https://crbug.com/1249810
- https://www.debian.org/security/2022/dsa-5046
