CVE-2021-4317 – This is a use-after-free vulnerability in ANGLE... (How to Fix)

Q: What is the severity of CVE-2021-4317?

CVE-2021-4317 has a CVSS score of 8.8 (HIGH). This is a use-after-free vulnerability in ANGLE (Almost Native Graphics Layer Engine) component of Google Chrome that allows arbitrary read/write operations. Attackers can exploit this via crafted HTML pages to potentially execute arbitrary code. All Chrome users prior to version 96.0.4664.93 are affected.

📋 TL;DR

This is a use-after-free vulnerability in ANGLE (Almost Native Graphics Layer Engine) component of Google Chrome that allows arbitrary read/write operations. Attackers can exploit this via crafted HTML pages to potentially execute arbitrary code. All Chrome users prior to version 96.0.4664.93 are affected.

💻 Affected Systems

Products:

Google Chrome
Chromium-based browsers
Microsoft Edge (Chromium-based)

Versions: All versions prior to 96.0.4664.93

Operating Systems: Windows, macOS, Linux, Android, Chrome OS

Default Config Vulnerable: ⚠️ Yes

Notes: All default Chrome installations are vulnerable. Other Chromium-based browsers 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

Arbitrary memory read/write leading to information disclosure, browser crashes, or sandbox escape.

🟢

If Mitigated

Browser crash with no code execution if sandbox holds, or limited impact if exploit fails.

🌐 Internet-Facing: HIGH - Exploitable via visiting malicious websites or viewing crafted content.

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

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires user interaction (visiting malicious page) but no authentication. No public exploit code is known.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 96.0.4664.93 and later

Vendor Advisory: https://chromereleases.googleblog.com/2021/12/stable-channel-update-for-desktop.html

Restart Required: Yes

Instructions:

1. Open Chrome menu > Help > About Google Chrome. 2. Chrome will automatically check for updates. 3. If update is available, click 'Relaunch' to apply. 4. For enterprise deployments, use Chrome Enterprise policies to deploy updates.

🔧 Temporary Workarounds

Disable JavaScript

all

Prevents exploitation by disabling JavaScript execution in Chrome

chrome://settings/content/javascript > Block

Enable Site Isolation

all

Enhances sandboxing to limit impact of potential exploits

chrome://flags/#enable-site-per-process > Enable

🧯 If You Can't Patch

Use alternative browsers temporarily
Implement network filtering to block known malicious sites

🔍 How to Verify

Check if Vulnerable:

Check Chrome version via chrome://version and compare to 96.0.4664.93

Check Version:

chrome://version (Windows/Linux/macOS) or chrome --version (command line)

Verify Fix Applied:

Confirm Chrome version is 96.0.4664.93 or higher

📡 Detection & Monitoring

Log Indicators:

Chrome crash reports with ANGLE-related stack traces
Unexpected Chrome process termination

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="process_termination") AND process_name="chrome.exe"

📊 Metadata

CVE ID: CVE-2021-4317

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: July 29, 2023

Last Updated: November 21, 2024

🔗 References

https://chromereleases.googleblog.com/2021/12/stable-channel-update-for-desktop.html Release Notes,Vendor Advisory
https://crbug.com/1260783 Exploit,Issue Tracking,Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PQKT7EGDD2P3L7S3NXEDDRCPK4NNZNWJ/
https://chromereleases.googleblog.com/2021/12/stable-channel-update-for-desktop.html Release Notes,Vendor Advisory
https://crbug.com/1260783 Exploit,Issue Tracking,Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PQKT7EGDD2P3L7S3NXEDDRCPK4NNZNWJ/

📤 Share & Export

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🔗 Related Vulnerabilities

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