CVE-2024-3840 – This vulnerability allows a remote attacker to ... (How to Fix)

Q: What is the severity of CVE-2024-3840?

CVE-2024-3840 has a CVSS score of 7.5 (HIGH). This vulnerability allows a remote attacker to bypass Chrome's Site Isolation security boundaries by crafting a malicious HTML page. Attackers could potentially access cross-origin data or perform unauthorized actions. All users running vulnerable Chrome versions are affected.

📋 TL;DR

This vulnerability allows a remote attacker to bypass Chrome's Site Isolation security boundaries by crafting a malicious HTML page. Attackers could potentially access cross-origin data or perform unauthorized actions. All users running vulnerable Chrome versions are affected.

💻 Affected Systems

Products:

Google Chrome
Chromium-based browsers

Versions: All versions prior to 124.0.6367.60

Operating Systems: Windows, Linux, macOS, ChromeOS

Default Config Vulnerable: ⚠️ Yes

Notes: All standard Chrome installations are vulnerable; Site Isolation is enabled by default.

📦 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

Complete bypass of Chrome's Site Isolation protections, allowing attackers to access sensitive cross-origin data including authentication tokens, personal information, or perform actions in other sites.

🟠

Likely Case

Limited data leakage or unauthorized actions within browser sessions, potentially enabling session hijacking or credential theft.

🟢

If Mitigated

Minimal impact with proper browser updates and security controls; isolated browsing sessions prevent significant damage.

🌐 Internet-Facing: HIGH - Attackers can exploit via malicious websites or ads without user interaction.

🏢 Internal Only: MEDIUM - Requires user to visit malicious internal pages; lower exposure than internet-facing.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploitation requires user to visit malicious webpage; no authentication needed.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 124.0.6367.60 and later

Vendor Advisory: https://chromereleases.googleblog.com/2024/04/stable-channel-update-for-desktop_16.html

Restart Required: Yes

Instructions:

1. Open Chrome settings 2. Click 'About Chrome' 3. Chrome will automatically check for and install updates 4. Restart Chrome when prompted

🔧 Temporary Workarounds

Disable JavaScript

all

Temporarily disable JavaScript to prevent exploitation

chrome://settings/content/javascript

Use Site Isolation Exceptions

all

Configure Site Isolation to block suspicious sites

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

🧯 If You Can't Patch

Use alternative browsers until Chrome can be updated
Implement network filtering to block known malicious domains

🔍 How to Verify

Check if Vulnerable:

Check Chrome version in settings; if below 124.0.6367.60, you are vulnerable.

Check Version:

chrome://version/

Verify Fix Applied:

Verify Chrome version is 124.0.6367.60 or higher after update.

📡 Detection & Monitoring

Log Indicators:

Unusual cross-origin requests
Multiple navigation attempts to different origins

Network Indicators:

Traffic to known malicious domains hosting exploit code

SIEM Query:

source="chrome" AND (event="navigation" OR event="security") AND status="blocked"

📊 Metadata

CVE ID: CVE-2024-3840

CVSS v3 Score: 7.5 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CWE: CWE-285

Published: April 17, 2024

Last Updated: December 19, 2024

🔗 References

📤 Share & Export

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📋 TL;DR

💻 Affected Systems

📦 What is this software?

Chrome by Google

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⚠️ Risk & Real-World Impact

Worst Case

Likely Case

If Mitigated

🎯 Exploit Status

🛠️ Fix & Mitigation

✅ Official Fix

Instructions:

🔧 Temporary Workarounds

Disable JavaScript

Use Site Isolation Exceptions

🧯 If You Can't Patch

🔍 How to Verify

Check if Vulnerable:

Check Version:

Verify Fix Applied:

📡 Detection & Monitoring

Log Indicators:

Network Indicators:

SIEM Query:

📊 Metadata

🔗 References

📤 Share & Export

🔗 Related Vulnerabilities