CVE-2021-30522 – This is a use-after-free vulnerability in Chrom... (How to Fix)

Q: What is the severity of CVE-2021-30522?

CVE-2021-30522 has a CVSS score of 8.8 (HIGH). This is a use-after-free vulnerability in Chrome's WebAudio component that allows remote attackers to potentially exploit heap corruption. Attackers can trigger this by tricking users into visiting a malicious HTML page. All Chrome users prior to version 91.0.4472.77 are affected.

📋 TL;DR

This is a use-after-free vulnerability in Chrome's WebAudio component that allows remote attackers to potentially exploit heap corruption. Attackers can trigger this by tricking users into visiting a malicious HTML page. All Chrome users prior to version 91.0.4472.77 are affected.

💻 Affected Systems

Products:

Google Chrome
Chromium-based browsers

Versions: All versions prior to 91.0.4472.77

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

Default Config Vulnerable: ⚠️ Yes

Notes: All standard Chrome installations are vulnerable. Embedded Chrome components in other applications may also be affected.

📦 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 complete system compromise, data theft, or ransomware deployment.

🟠

Likely Case

Browser crash (denial of service) or limited code execution within the browser sandbox.

🟢

If Mitigated

No impact if Chrome is updated to patched version or if exploit attempts are blocked by security controls.

🌐 Internet-Facing: HIGH - Attackers can exploit via malicious websites without user interaction beyond visiting the page.

🏢 Internal Only: MEDIUM - Requires user to visit malicious internal page, but could be used in targeted attacks.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires bypassing Chrome's sandbox and other security mitigations, but use-after-free vulnerabilities are commonly exploited.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 91.0.4472.77 and later

Vendor Advisory: https://chromereleases.googleblog.com/2021/05/stable-channel-update-for-desktop_25.html

Restart Required: Yes

Instructions:

1. Open Chrome and click the three-dot menu. 2. Go to Help > About Google Chrome. 3. Chrome will automatically check for and install updates. 4. Click 'Relaunch' to restart Chrome with the update.

🔧 Temporary Workarounds

Disable JavaScript

all

Prevents execution of malicious JavaScript that could trigger the vulnerability

Use Chrome Site Isolation

all

Enhances sandboxing to limit impact of potential exploitation

🧯 If You Can't Patch

Restrict access to untrusted websites using web filtering or proxy controls
Implement application whitelisting to prevent execution of malicious payloads

🔍 How to Verify

Check if Vulnerable:

Open Chrome, go to chrome://version and check if version is less than 91.0.4472.77

Check Version:

google-chrome --version

Verify Fix Applied:

Confirm Chrome version is 91.0.4472.77 or higher in chrome://version

📡 Detection & Monitoring

Log Indicators:

Chrome crash reports
Unexpected WebAudio process termination
Memory access violation errors

Network Indicators:

Requests to known malicious domains hosting exploit code
Unusual WebAudio API calls

SIEM Query:

source="chrome" AND (event="crash" OR event="memory_violation") AND process="chrome"

📊 Metadata

CVE ID: CVE-2021-30522

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: June 7, 2021

Last Updated: November 21, 2024

🔗 References

https://chromereleases.googleblog.com/2021/05/stable-channel-update-for-desktop_25.html Release Notes,Vendor Advisory
https://crbug.com/1176218 Exploit,Issue Tracking,Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ETMZL6IHCTCTREEL434BQ4THQ7EOHJ43/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PAT6EOXVQFE6JFMFQF4IKAOUQSHMHL54/
https://security.gentoo.org/glsa/202107-06 Third Party Advisory
https://www.talosintelligence.com/vulnerability_reports/TALOS-2021-1251 Third Party Advisory
https://chromereleases.googleblog.com/2021/05/stable-channel-update-for-desktop_25.html Release Notes,Vendor Advisory
https://crbug.com/1176218 Exploit,Issue Tracking,Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ETMZL6IHCTCTREEL434BQ4THQ7EOHJ43/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PAT6EOXVQFE6JFMFQF4IKAOUQSHMHL54/
https://security.gentoo.org/glsa/202107-06 Third Party Advisory
https://www.talosintelligence.com/vulnerability_reports/TALOS-2021-1251 Third Party Advisory

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🔗 Related Vulnerabilities

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