CVE-2021-30581
📋 TL;DR
This is a use-after-free vulnerability in Chrome DevTools that allows heap corruption when a user with a malicious extension visits a crafted HTML page. Attackers could potentially execute arbitrary code or cause browser crashes. All Chrome users prior to version 92.0.4515.107 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...
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⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to full system compromise, data theft, or malware installation.
Likely Case
Browser crash or instability, with potential for limited code execution in browser context.
If Mitigated
No impact if Chrome is updated or malicious extensions are prevented.
🎯 Exploit Status
Requires social engineering to install malicious extension plus visiting malicious page.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 92.0.4515.107
Vendor Advisory: https://chromereleases.googleblog.com/2021/07/stable-channel-update-for-desktop_20.html
Restart Required: Yes
Instructions:
1. Open Chrome. 2. Click three dots menu → Help → About Google Chrome. 3. Chrome will auto-update if available. 4. Click Relaunch to restart.
🔧 Temporary Workarounds
Disable Chrome auto-updates
allPrevent automatic updates to maintain control (not recommended long-term).
# Linux: sudo apt-mark hold google-chrome-stable
# Windows: Disable via Group Policy or registry
Restrict extension installation
allOnly allow extensions from Chrome Web Store or block all extensions.
# Chrome policy: ExtensionInstallBlocklist to block all
# ExtensionInstallAllowlist to whitelist
🧯 If You Can't Patch
- Implement strict extension whitelisting policies.
- Use web filtering to block known malicious sites and untrusted HTML content.
🔍 How to Verify
Check if Vulnerable:
Check Chrome version via chrome://version/ and compare to 92.0.4515.107.Check Version:
google-chrome --versionVerify Fix Applied:
Confirm Chrome version is 92.0.4515.107 or later.📡 Detection & Monitoring
Log Indicators:
- Chrome crash reports with memory corruption signatures
- Unexpected extension installation events
Network Indicators:
- Requests to known malicious domains hosting crafted HTML
SIEM Query:
source="chrome_logs" AND (event="crash" OR event="extension_install")🔗 References
- https://chromereleases.googleblog.com/2021/07/stable-channel-update-for-desktop_20.html
- https://crbug.com/1194431
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5LVY4WIWTVVYKQMROJJS365TZBKEARCF/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IPJPUSAWIJMQFBQQQYXAICLI4EKFQOH6/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QW4R2K5HVJ4R6XDZYOJCCFPIN2XHNS3L/
- https://chromereleases.googleblog.com/2021/07/stable-channel-update-for-desktop_20.html
- https://crbug.com/1194431
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5LVY4WIWTVVYKQMROJJS365TZBKEARCF/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IPJPUSAWIJMQFBQQQYXAICLI4EKFQOH6/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QW4R2K5HVJ4R6XDZYOJCCFPIN2XHNS3L/
