CVE-2021-38005 – This is a use-after-free vulnerability in Chrom... (How to Fix)

Q: What is the severity of CVE-2021-38005?

CVE-2021-38005 has a CVSS score of 8.8 (HIGH). This is a use-after-free vulnerability in Chrome's loader component that allows remote attackers to potentially exploit heap corruption via a crafted HTML page. Attackers could execute arbitrary code or cause browser crashes. All users running vulnerable Chrome versions are affected.

📋 TL;DR

This is a use-after-free vulnerability in Chrome's loader component that allows remote attackers to potentially exploit heap corruption via a crafted HTML page. Attackers could execute arbitrary code or cause browser crashes. All users running vulnerable Chrome versions are affected.

💻 Affected Systems

Products:

Google Chrome

Versions: All versions prior to 96.0.4664.45

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

Default Config Vulnerable: ⚠️ Yes

Notes: All Chrome-based browsers (Chromium, Edge, etc.) may be affected if using vulnerable Chromium versions.

📦 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 malware installation.

🟠

Likely Case

Browser crashes, denial of service, or limited code execution in sandboxed context.

🟢

If Mitigated

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

🌐 Internet-Facing: HIGH - Exploitable via visiting malicious websites, making internet-facing systems particularly vulnerable.

🏢 Internal Only: MEDIUM - Still exploitable via internal phishing or compromised internal websites.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires user interaction (visiting malicious page) but no authentication. Use-after-free vulnerabilities often require specific heap grooming.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 96.0.4664.45 and later

Vendor Advisory: https://chromereleases.googleblog.com/2021/11/stable-channel-update-for-desktop.html

Restart Required: Yes

Instructions:

1. Open Chrome. 2. Click three-dot menu → 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 exploitation by disabling JavaScript execution, which is required for the crafted HTML page to trigger the vulnerability.

chrome://settings/content/javascript → Block

Use Site Isolation

all

Enables site isolation to limit impact if exploitation occurs.

chrome://flags/#site-isolation-trial-opt-out → Disabled

🧯 If You Can't Patch

Use alternative browser temporarily
Implement web filtering to block known malicious sites

🔍 How to Verify

Check if Vulnerable:

Check Chrome version: chrome://version and compare to vulnerable range (< 96.0.4664.45).

Check Version:

chrome://version or 'google-chrome --version' on Linux/macOS terminal

Verify Fix Applied:

Confirm Chrome version is 96.0.4664.45 or higher via chrome://version.

📡 Detection & Monitoring

Log Indicators:

Chrome crash reports
Unexpected process terminations
Sandbox escape attempts in logs

Network Indicators:

Requests to known exploit hosting domains
Unusual outbound connections from Chrome processes

SIEM Query:

process_name:"chrome.exe" AND (event_id:1000 OR event_id:1001) OR http_user_agent:"*Chrome/9[0-5].*"

📊 Metadata

CVE ID: CVE-2021-38005

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: December 23, 2021

Last Updated: November 21, 2024

🔗 References

https://chromereleases.googleblog.com/2021/11/stable-channel-update-for-desktop.html Vendor Advisory
https://crbug.com/1241091 Permissions Required
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3W46HRT2UVHWSLZB6JZHQF6JNQWKV744/
https://www.debian.org/security/2022/dsa-5046 Third Party Advisory
https://chromereleases.googleblog.com/2021/11/stable-channel-update-for-desktop.html Vendor Advisory
https://crbug.com/1241091 Permissions Required
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3W46HRT2UVHWSLZB6JZHQF6JNQWKV744/
https://www.debian.org/security/2022/dsa-5046 Third Party Advisory

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🔗 Related Vulnerabilities

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