CVE-2021-21152
📋 TL;DR
This vulnerability is a heap buffer overflow in Chrome's Media component on Linux systems. It allows remote attackers to potentially execute arbitrary code or cause denial of service by tricking users into visiting a malicious HTML page. Users running Chrome on Linux prior to version 88.0.4324.182 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 ransomware deployment.
Likely Case
Browser crash (denial of service) or limited code execution within browser sandbox.
If Mitigated
No impact if Chrome is fully patched or if exploit attempts are blocked by security controls.
🎯 Exploit Status
Exploitation requires heap manipulation techniques but is facilitated by the unauthenticated nature of the attack vector.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 88.0.4324.182
Vendor Advisory: https://chromereleases.googleblog.com/2021/02/stable-channel-update-for-desktop_16.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 apply updates. 4. Restart Chrome when prompted.
🔧 Temporary Workarounds
Disable JavaScript
allPrevents execution of malicious scripts that could trigger the vulnerability.
chrome://settings/content/javascript → toggle off
Use Site Isolation
allLimits impact by isolating websites in separate processes.
chrome://flags/#enable-site-per-process → enable
🧯 If You Can't Patch
- Restrict web browsing to trusted sites only using network policies.
- Deploy web application firewall (WAF) rules to block suspicious HTML content.
🔍 How to Verify
Check if Vulnerable:
Check Chrome version: if on Linux and version is less than 88.0.4324.182, it is vulnerable.Check Version:
google-chrome --versionVerify Fix Applied:
Confirm Chrome version is 88.0.4324.182 or higher after update.📡 Detection & Monitoring
Log Indicators:
- Chrome crash logs with memory corruption errors
- Unusual process spawns from Chrome
Network Indicators:
- HTTP requests to known malicious domains hosting exploit code
SIEM Query:
source="chrome" AND (event="crash" OR event="memory_error")🔗 References
- https://chromereleases.googleblog.com/2021/02/stable-channel-update-for-desktop_16.html
- https://crbug.com/1166504
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BI6ZIJQYP5DFMYVX4J5OGOU2NQLEZ3SB/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FE5SIKEVYTMDCC5OSXGOM2KRPYLHYMQX/
- https://security.gentoo.org/glsa/202104-08
- https://chromereleases.googleblog.com/2021/02/stable-channel-update-for-desktop_16.html
- https://crbug.com/1166504
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BI6ZIJQYP5DFMYVX4J5OGOU2NQLEZ3SB/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FE5SIKEVYTMDCC5OSXGOM2KRPYLHYMQX/
- https://security.gentoo.org/glsa/202104-08
