CVE-2022-0306 – This vulnerability is a heap buffer overflow in... (How to Fix)

Q: What is the severity of CVE-2022-0306?

CVE-2022-0306 has a CVSS score of 8.8 (HIGH). This vulnerability is a heap buffer overflow in PDFium, Chrome's PDF rendering engine, that allows remote attackers to potentially exploit heap corruption via a crafted HTML page. It affects Google Chrome users prior to version 97.0.4692.99, potentially leading to arbitrary code execution or browser crashes.

📋 TL;DR

This vulnerability is a heap buffer overflow in PDFium, Chrome's PDF rendering engine, that allows remote attackers to potentially exploit heap corruption via a crafted HTML page. It affects Google Chrome users prior to version 97.0.4692.99, potentially leading to arbitrary code execution or browser crashes.

💻 Affected Systems

Products:

Google Chrome
Chromium-based browsers

Versions: All versions prior to 97.0.4692.99

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

Default Config Vulnerable: ⚠️ Yes

Notes: All Chrome installations with PDF rendering enabled (default) are vulnerable. Chromium-based browsers may also be affected depending on their PDFium version.

📦 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 with the same privileges as the Chrome process, potentially leading to full system compromise if Chrome is running with elevated privileges.

🟠

Likely Case

Browser crash (denial of service) or limited code execution within Chrome's sandbox, potentially allowing data theft or further exploitation.

🟢

If Mitigated

No impact if Chrome is fully patched or if exploit attempts are blocked by security controls.

🌐 Internet-Facing: HIGH - Attackers can exploit via malicious websites or PDF files without user interaction beyond visiting a page.

🏢 Internal Only: MEDIUM - Requires user to visit malicious content, which could be delivered via internal phishing or compromised sites.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Proof-of-concept code is publicly available. Exploitation requires bypassing Chrome's sandbox for full impact, but denial of service is trivial.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 97.0.4692.99 and later

Vendor Advisory: https://chromereleases.googleblog.com/2022/01/stable-channel-update-for-desktop_19.html

Restart Required: Yes

Instructions:

1. Open Chrome. 2. Click the 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 PDF rendering in Chrome

all

Prevents Chrome from using PDFium to render PDF files, forcing download instead.

chrome://settings/content/pdfDocuments → Toggle 'Download PDF files instead of automatically opening them in Chrome'

Use alternative PDF viewer

all

Configure Chrome to use external PDF viewers instead of built-in PDFium.

chrome://settings/content/pdfDocuments → Toggle 'Open PDF files in the default system application'

🧯 If You Can't Patch

Block access to untrusted websites and PDF files via web proxy or firewall
Implement application whitelisting to prevent execution of malicious code if exploitation occurs

🔍 How to Verify

Check if Vulnerable:

Check Chrome version: If version is less than 97.0.4692.99, the system is vulnerable.

Check Version:

On Chrome: chrome://version or 'google-chrome --version' on command line

Verify Fix Applied:

Confirm Chrome version is 97.0.4692.99 or higher via chrome://version

📡 Detection & Monitoring

Log Indicators:

Chrome crash reports with PDFium or PDF-related modules in stack traces
Unexpected Chrome process termination events

Network Indicators:

HTTP requests to known malicious domains hosting exploit code
Downloads of suspicious PDF files

SIEM Query:

source="chrome_crash_reports" AND (process="chrome" OR module="pdfium") AND event_type="crash"

📊 Metadata

CVE ID: CVE-2022-0306

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-787

Published: February 12, 2022

Last Updated: November 21, 2024

🔗 References

http://packetstormsecurity.com/files/166367/Chrome-chrome_pdf-PDFiumEngine-RequestThumbnail-Heap-Buffer-Overflow.html Third Party Advisory,VDB Entry
https://chromereleases.googleblog.com/2022/01/stable-channel-update-for-desktop_19.html Release Notes,Vendor Advisory
https://crbug.com/1283198 Issue Tracking,Permissions Required,Third Party Advisory
http://packetstormsecurity.com/files/166367/Chrome-chrome_pdf-PDFiumEngine-RequestThumbnail-Heap-Buffer-Overflow.html Third Party Advisory,VDB Entry
https://chromereleases.googleblog.com/2022/01/stable-channel-update-for-desktop_19.html Release Notes,Vendor Advisory
https://crbug.com/1283198 Issue Tracking,Permissions Required,Third Party Advisory

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🔗 Related Vulnerabilities

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