CVE-2021-30565
📋 TL;DR
This vulnerability allows an attacker to perform out-of-bounds memory writes in Google Chrome's Tab Groups feature. By convincing a user to install a malicious extension and visit a crafted HTML page, an attacker could potentially execute arbitrary code. Affects Chrome users on Linux and ChromeOS who haven't updated to the patched version.
💻 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 installation of persistent malware.
Likely Case
Browser crash or limited memory corruption leading to instability, with potential for data exfiltration if combined with other vulnerabilities.
If Mitigated
No impact if Chrome is updated to patched version or if malicious extensions are prevented from installation.
🎯 Exploit Status
Exploitation requires social engineering to install malicious extension and visit malicious page. No public exploit code available.
🛠️ 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-dot menu → Help → About Google Chrome. 3. Chrome will automatically check for updates and install version 92.0.4515.107 or later. 4. Restart Chrome when prompted.
🔧 Temporary Workarounds
Disable extension installation
allPrevent users from installing extensions to block the attack vector.
# For enterprise: Use Chrome policies to disable extension installation
# For individual: Settings → Extensions → Disable developer mode/third-party extensions
Use alternative browser
linuxTemporarily switch to updated Firefox or other secure browser until Chrome is patched.
🧯 If You Can't Patch
- Implement strict extension whitelisting policies
- Deploy web filtering to block malicious HTML pages and restrict extension installation
🔍 How to Verify
Check if Vulnerable:
Check Chrome version: If version is below 92.0.4515.107 on Linux/ChromeOS, system is vulnerable.Check Version:
google-chrome --versionVerify Fix Applied:
Confirm Chrome version is 92.0.4515.107 or higher after update.📡 Detection & Monitoring
Log Indicators:
- Chrome crash logs with memory corruption errors
- Unexpected extension installation events
Network Indicators:
- Requests to known malicious domains hosting crafted HTML
- Unusual outbound connections after visiting suspicious pages
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/1210985
- 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/1210985
- 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/
