CVE-2021-4319
📋 TL;DR
This is a use-after-free vulnerability in Chrome's Blink rendering engine that allows remote attackers to perform arbitrary read/write operations via a crafted HTML page. It affects Google Chrome versions prior to 93.0.4577.82 and Chromium-based browsers. Users visiting malicious websites are at risk.
💻 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
Full system compromise including arbitrary code execution, data theft, and complete browser control
Likely Case
Arbitrary read/write leading to information disclosure, session hijacking, or limited code execution within browser sandbox
If Mitigated
No impact if browser is fully patched or exploit attempts are blocked by security controls
🎯 Exploit Status
Exploitation requires user to visit malicious website. No public exploit code available at disclosure.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 93.0.4577.82 and later
Vendor Advisory: https://chromereleases.googleblog.com/2021/09/stable-channel-update-for-desktop.html
Restart Required: Yes
Instructions:
1. Open Chrome menu > Help > About Google Chrome 2. Browser will automatically check for and apply update 3. Restart Chrome when prompted
🔧 Temporary Workarounds
Disable JavaScript
allTemporarily disable JavaScript to prevent exploitation via malicious websites
chrome://settings/content/javascript
Use site isolation
allEnsure site isolation is enabled for additional protection
chrome://flags/#site-isolation-trial-opt-out (set to Disabled)
🧯 If You Can't Patch
- Restrict browser usage to trusted websites only
- Implement network filtering to block malicious domains
🔍 How to Verify
Check if Vulnerable:
Check Chrome version in menu > Help > About Google ChromeCheck Version:
google-chrome --version (Linux) or chrome://versionVerify Fix Applied:
Confirm version is 93.0.4577.82 or higher📡 Detection & Monitoring
Log Indicators:
- Chrome crash reports with memory corruption signatures
- Unusual process behavior from chrome.exe
Network Indicators:
- Requests to known malicious domains hosting exploit code
- Unusual outbound connections from browser
SIEM Query:
process_name:chrome.exe AND (event_id:1000 OR memory_violation)🔗 References
- https://chromereleases.googleblog.com/2021/09/stable-channel-update-for-desktop.html
- https://crbug.com/1214199
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PQKT7EGDD2P3L7S3NXEDDRCPK4NNZNWJ/
- https://chromereleases.googleblog.com/2021/09/stable-channel-update-for-desktop.html
- https://crbug.com/1214199
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PQKT7EGDD2P3L7S3NXEDDRCPK4NNZNWJ/
