CVE-2021-21196
📋 TL;DR
This vulnerability allows a remote attacker to trigger a heap buffer overflow in Google Chrome's TabStrip component on Windows by luring users to a malicious HTML page. Successful exploitation could lead to heap corruption, potentially enabling arbitrary code execution. All Windows users running Chrome versions prior to 89.0.4389.114 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 with the privileges of the Chrome process, potentially leading to full system compromise if combined with privilege escalation.
Likely Case
Browser crash (denial of service) or limited code execution within Chrome's sandbox, potentially allowing data theft or further exploitation.
If Mitigated
No impact if Chrome is fully patched or if exploit attempts are blocked by security controls.
🎯 Exploit Status
Exploitation requires user interaction (visiting a malicious page) and bypassing Chrome's sandbox for full impact.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 89.0.4389.114
Vendor Advisory: https://chromereleases.googleblog.com/2021/03/stable-channel-update-for-desktop_30.html
Restart Required: Yes
Instructions:
1. Open Chrome. 2. Click the three-dot menu → Help → About Google Chrome. 3. Chrome will automatically check for and install updates. 4. Click 'Relaunch' to restart Chrome with the patched version.
🔧 Temporary Workarounds
Disable JavaScript
allPrevents malicious HTML pages from executing exploit code, but breaks most web functionality.
Use Chrome's Site Isolation
allEnhances sandboxing to limit impact of potential exploits.
🧯 If You Can't Patch
- Restrict browsing to trusted websites only.
- Deploy web filtering to block malicious HTML pages and use endpoint protection with exploit prevention.
🔍 How to Verify
Check if Vulnerable:
Check Chrome version: if below 89.0.4389.114 on Windows, it's vulnerable.Check Version:
chrome://version/Verify Fix Applied:
Confirm Chrome version is 89.0.4389.114 or higher.📡 Detection & Monitoring
Log Indicators:
- Chrome crash reports, unexpected process termination logs
Network Indicators:
- Requests to known malicious domains hosting exploit HTML
SIEM Query:
source="chrome" AND (event="crash" OR event="process_termination")🔗 References
- https://chromereleases.googleblog.com/2021/03/stable-channel-update-for-desktop_30.html
- https://crbug.com/1175992
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EAJ42L4JFPBJATCZ7MOZQTUDGV4OEHHG/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U3GZ42MYPGD35V652ZPVPYYS7A7LVXVY/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VUZBGKGVZADNA3I24NVG7HAYYUTOSN5A/
- https://security.gentoo.org/glsa/202104-08
- https://chromereleases.googleblog.com/2021/03/stable-channel-update-for-desktop_30.html
- https://crbug.com/1175992
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EAJ42L4JFPBJATCZ7MOZQTUDGV4OEHHG/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U3GZ42MYPGD35V652ZPVPYYS7A7LVXVY/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VUZBGKGVZADNA3I24NVG7HAYYUTOSN5A/
- https://security.gentoo.org/glsa/202104-08
