CVE-2021-30616 – CVE-2021-30616 is a use-after-free vulnerabilit... (How to Fix)

Q: What is the severity of CVE-2021-30616?

CVE-2021-30616 has a CVSS score of 8.8 (HIGH). CVE-2021-30616 is a use-after-free vulnerability in Chromium's media component that allows remote attackers to execute arbitrary code or cause denial of service via a crafted HTML page. This affects all Chromium-based browsers including Google Chrome, Microsoft Edge, and other derivatives. Users who visit malicious websites with vulnerable browser versions are at risk.

📋 TL;DR

CVE-2021-30616 is a use-after-free vulnerability in Chromium's media component that allows remote attackers to execute arbitrary code or cause denial of service via a crafted HTML page. This affects all Chromium-based browsers including Google Chrome, Microsoft Edge, and other derivatives. Users who visit malicious websites with vulnerable browser versions are at risk.

💻 Affected Systems

Products:

Google Chrome
Microsoft Edge
Chromium-based browsers

Versions: Chromium versions before 93.0.4577.82

Operating Systems: Windows, Linux, macOS, Android, iOS

Default Config Vulnerable: ⚠️ Yes

Notes: All default configurations of affected browsers are vulnerable.

📦 What is this software?

⚠️ 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 in browser sandbox.

🟢

If Mitigated

No impact if patched; sandboxing may limit exploit effectiveness even if vulnerable.

🌐 Internet-Facing: HIGH - Exploitable via visiting malicious websites.

🏢 Internal Only: MEDIUM - Could be exploited via internal phishing or compromised sites.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires user interaction (visiting malicious site) but no authentication.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Chrome/Edge 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 browser settings 2. Navigate to 'About Chrome/Edge' 3. Allow browser to check for and install updates 4. Restart browser when prompted

🔧 Temporary Workarounds

Disable JavaScript

all

Prevents exploitation by disabling JavaScript execution in browser

Use browser extensions to block scripts

all

Install script-blocking extensions like NoScript or uBlock Origin

🧯 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 browser version in settings; if below 93.0.4577.82, you are vulnerable.

Check Version:

chrome://version/ or edge://version/

Verify Fix Applied:

Confirm browser version is 93.0.4577.82 or higher after update.

📡 Detection & Monitoring

Log Indicators:

Browser crash reports
Unexpected process termination

Network Indicators:

Connections to known malicious domains
Suspicious JavaScript execution patterns

SIEM Query:

source="browser_logs" AND (event="crash" OR event="process_termination")

📊 Metadata

CVE ID: CVE-2021-30616

CVSS v3 Score: 8.8 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CWE: CWE-416

Published: September 3, 2021

Last Updated: November 21, 2024

🔗 References

📤 Share & Export

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🔗 Related Vulnerabilities

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