CVE-2021-37979
📋 TL;DR
This vulnerability is a heap buffer overflow in WebRTC in Google Chrome that allows remote attackers to potentially exploit heap corruption. Attackers can trigger this by convincing users to visit a malicious website with a crafted HTML page. All users running vulnerable versions of Chrome are affected.
💻 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 →Fedora by Fedoraproject
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to full system compromise, data theft, or ransomware deployment.
Likely Case
Browser crash, denial of service, or limited information disclosure.
If Mitigated
No impact if Chrome is updated to patched version or if exploit attempts are blocked by security controls.
🎯 Exploit Status
Exploitation requires user interaction (visiting malicious site) but no authentication. Technical details available in public references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 94.0.4606.81 and later
Vendor Advisory: https://chromereleases.googleblog.com/2021/10/stable-channel-update-for-desktop.html
Restart Required: Yes
Instructions:
1. Open Chrome. 2. Click three-dot menu → Help → About Google Chrome. 3. Chrome will automatically check for and install updates. 4. Click 'Relaunch' to restart Chrome with the update.
🔧 Temporary Workarounds
Disable WebRTC
allTemporarily disable WebRTC functionality to prevent exploitation
chrome://flags/#disable-webrtc
Use browser extensions to block WebRTC
allInstall extensions like WebRTC Control or WebRTC Leak Prevent
🧯 If You Can't Patch
- Use alternative browsers until Chrome can be updated
- Implement network filtering to block known malicious domains and restrict browser access
🔍 How to Verify
Check if Vulnerable:
Check Chrome version: Open Chrome → Click three-dot menu → Help → About Google Chrome. If version is below 94.0.4606.81, you are vulnerable.Check Version:
On Windows: "C:\Program Files\Google\Chrome\Application\chrome.exe" --version
On macOS: /Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --version
On Linux: google-chrome --versionVerify Fix Applied:
After updating, verify Chrome version is 94.0.4606.81 or higher using the same About Google Chrome page.📡 Detection & Monitoring
Log Indicators:
- Chrome crash reports
- Unexpected browser termination events
- Security event logs showing heap corruption
Network Indicators:
- Traffic to suspicious domains with WebRTC-related requests
- Unusual WebRTC connection attempts
SIEM Query:
source="chrome_logs" AND (event="crash" OR event="heap_corruption") AND version<"94.0.4606.81"🔗 References
- https://chromereleases.googleblog.com/2021/10/stable-channel-update-for-desktop.html
- https://crbug.com/1247260
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RNARCF5HEZK7GJXZRN5TQ45AQDCRM2WO/
- https://www.debian.org/security/2022/dsa-5046
- https://www.talosintelligence.com/vulnerability_reports/TALOS-2021-1372
- https://chromereleases.googleblog.com/2021/10/stable-channel-update-for-desktop.html
- https://crbug.com/1247260
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RNARCF5HEZK7GJXZRN5TQ45AQDCRM2WO/
- https://www.debian.org/security/2022/dsa-5046
- https://www.talosintelligence.com/vulnerability_reports/TALOS-2021-1372
