CVE-2021-37962 – This is a use-after-free vulnerability in Chrom... (How to Fix)

Q: What is the severity of CVE-2021-37962?

CVE-2021-37962 has a CVSS score of 8.8 (HIGH). This is a use-after-free vulnerability in Chrome's Performance Manager component that allows a remote attacker who has already compromised the renderer process to potentially exploit heap corruption. Attackers could execute arbitrary code or cause crashes by tricking users into visiting a malicious HTML page. All Chrome users prior to version 94.0.4606.54 are affected.

📋 TL;DR

This is a use-after-free vulnerability in Chrome's Performance Manager component that allows a remote attacker who has already compromised the renderer process to potentially exploit heap corruption. Attackers could execute arbitrary code or cause crashes by tricking users into visiting a malicious HTML page. All Chrome users prior to version 94.0.4606.54 are affected.

💻 Affected Systems

Products:

Google Chrome

Versions: All versions prior to 94.0.4606.54

Operating Systems: Windows, Linux, macOS, ChromeOS

Default Config Vulnerable: ⚠️ Yes

Notes: Chromium-based browsers may also be affected. Requires renderer process compromise first.

📦 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...

Learn more about Chrome →

⚠️ 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 sandbox constraints.

🟢

If Mitigated

No impact if Chrome is fully patched or if renderer process compromise is prevented.

🌐 Internet-Facing: HIGH - Exploitable via malicious web content without authentication.

🏢 Internal Only: MEDIUM - Requires user interaction with malicious content, which could be delivered internally.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Requires chaining with another vulnerability to compromise renderer process first. No public exploit code known.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 94.0.4606.54

Vendor Advisory: https://chromereleases.googleblog.com/2021/09/stable-channel-update-for-desktop_21.html

Restart Required: Yes

Instructions:

1. Open Chrome. 2. Click menu (three dots) > Help > About Google Chrome. 3. Chrome will automatically check for and install updates. 4. Click 'Relaunch' to restart Chrome.

🔧 Temporary Workarounds

Disable JavaScript

all

Prevents execution of malicious JavaScript that could trigger the vulnerability.

chrome://settings/content/javascript

Use Site Isolation

all

Enforces process separation between websites to limit impact.

chrome://flags/#site-isolation-trial-opt-out (set to Disabled)

🧯 If You Can't Patch

Deploy network filtering to block known malicious domains.
Implement application allowlisting to prevent unauthorized Chrome execution.

🔍 How to Verify

Check if Vulnerable:

Check Chrome version: if below 94.0.4606.54, system is vulnerable.

Check Version:

google-chrome --version (Linux) or chrome://version (all platforms)

Verify Fix Applied:

Confirm Chrome version is 94.0.4606.54 or higher.

📡 Detection & Monitoring

Log Indicators:

Chrome crash reports
Renderer process termination logs
Unexpected memory access errors

Network Indicators:

Requests to known malicious domains hosting exploit code
Unusual outbound connections after visiting suspicious sites

SIEM Query:

source="chrome" AND (event="crash" OR event="renderer_killed")

📊 Metadata

CVE ID: CVE-2021-37962

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: October 8, 2021

Last Updated: November 21, 2024

🔗 References

https://chromereleases.googleblog.com/2021/09/stable-channel-update-for-desktop_21.html Release Notes,Vendor Advisory
https://crbug.com/1231933 Permissions Required,Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4DDW7HAHTS3SDVXBQUY4SURELO5D4X7R/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PM7MOYYHJSWLIFZ4TPJTD7MSA3HSSLV2/
https://www.debian.org/security/2022/dsa-5046 Third Party Advisory
https://chromereleases.googleblog.com/2021/09/stable-channel-update-for-desktop_21.html Release Notes,Vendor Advisory
https://crbug.com/1231933 Permissions Required,Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4DDW7HAHTS3SDVXBQUY4SURELO5D4X7R/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PM7MOYYHJSWLIFZ4TPJTD7MSA3HSSLV2/
https://www.debian.org/security/2022/dsa-5046 Third Party Advisory

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🔗 Related Vulnerabilities

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