CVE-2025-13720: Google Chrome RCE Vulnerability

CVE-2025-13720 Overview

CVE-2025-13720 is a type confusion vulnerability (bad cast) in the Loader component of Google Chrome prior to version 143.0.7499.41. This flaw allows a remote attacker who has already compromised the renderer process to potentially exploit heap corruption through a specially crafted HTML page. The vulnerability is classified under CWE-704 (Incorrect Type Conversion or Cast), indicating improper handling of type conversions within the browser's loader functionality.

Critical Impact

An attacker with control over a compromised renderer process can leverage this bad cast vulnerability to corrupt heap memory, potentially leading to arbitrary code execution within the browser context.

Affected Products

• Google Chrome prior to version 143.0.7499.41 on Windows
• Google Chrome prior to version 143.0.7499.41 on macOS
• Google Chrome prior to version 143.0.7499.41 on Linux

Discovery Timeline

• 2025-12-02 - CVE-2025-13720 published to NVD
• 2025-12-04 - Last updated in NVD database

Technical Details for CVE-2025-13720

Vulnerability Analysis

This vulnerability stems from a bad cast operation within Google Chrome's Loader component. A bad cast occurs when the program incorrectly converts an object from one type to another without proper validation, leading to type confusion. In this case, the Loader component fails to properly verify the type of an object before casting it, which can result in the program operating on memory with incorrect assumptions about its structure.

The attack requires the adversary to first compromise the renderer process, which serves as a prerequisite condition. Once the renderer is compromised, the attacker can craft malicious HTML content that triggers the bad cast condition in the Loader component. This subsequently leads to heap corruption, where memory structures are overwritten in unintended ways.

The exploitation chain requires user interaction—specifically, a victim must visit a malicious web page. The network-based attack vector combined with the requirement for renderer compromise indicates this is likely part of a multi-stage attack scenario, potentially used as a sandbox escape technique.

Root Cause

The root cause is improper type validation in the Loader component's casting operations. When processing certain objects, the code performs a type cast without adequately verifying that the source object is of the expected type. This violates the principle of type safety and allows an attacker to supply an object of an unexpected type, leading to memory corruption when the cast object is subsequently accessed.

Attack Vector

The attack vector is network-based and requires user interaction. An attacker must first gain control of the renderer process through a separate vulnerability or exploit chain. With renderer access, they can then serve or inject a crafted HTML page that triggers the bad cast vulnerability in the Loader component. The crafted page causes the Loader to incorrectly cast an object, corrupting heap memory and potentially enabling further exploitation such as code execution or sandbox escape.

The vulnerability is exploitable by delivering malicious content through:

• Compromised or malicious websites
• Malicious advertisements (malvertising)
• Injected content on legitimate sites via XSS or similar attacks

Detection Methods for CVE-2025-13720

Indicators of Compromise

• Unusual Chrome renderer process crashes or restarts, particularly when visiting unfamiliar websites
• Memory access violations or heap corruption errors in Chrome crash logs
• Anomalous network connections following browser rendering operations
• Unexpected child process spawning from Chrome browser processes

Detection Strategies

• Monitor for Chrome crash reports indicating heap corruption in the Loader component
• Implement endpoint detection rules for suspicious browser behavior patterns
• Deploy web content filtering to block access to known malicious domains exploiting browser vulnerabilities
• Enable Chrome's built-in crash reporting and analyze reports for patterns consistent with type confusion exploitation

Monitoring Recommendations

• Review Chrome browser version inventory across the organization to identify unpatched instances
• Monitor endpoint telemetry for abnormal memory allocation patterns in browser processes
• Implement network monitoring to detect connections to suspicious domains following browser activity
• Enable SentinelOne's browser process monitoring capabilities to detect anomalous renderer behavior

How to Mitigate CVE-2025-13720

Immediate Actions Required

• Update Google Chrome to version 143.0.7499.41 or later immediately across all systems
• Enable automatic Chrome updates to ensure timely deployment of security patches
• Consider using enterprise browser management tools to enforce version compliance
• Implement network segmentation to limit potential lateral movement if exploitation occurs

Patch Information

Google has released a security update addressing this vulnerability in Chrome version 143.0.7499.41. The patch corrects the type casting issue in the Loader component to prevent heap corruption. Organizations should reference the Google Chrome Desktop Update announcement for complete details on the security update.

Additional technical information may be available through the Chromium Issue Tracker Entry.

Workarounds

• If immediate patching is not possible, consider restricting browser access to untrusted websites via web filtering
• Enable Chrome's Site Isolation feature if not already active to limit renderer compromise impact
• Implement strict Content Security Policies on organization-owned web properties to reduce attack surface
• Consider using application sandboxing solutions to add an additional layer of protection around browser processes

# Verify Chrome version from command line
# On Windows (PowerShell):
(Get-Item "C:\Program Files\Google\Chrome\Application\chrome.exe").VersionInfo.ProductVersion

# On macOS:
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --version

# On Linux:
google-chrome --version

# Ensure version is 143.0.7499.41 or later