CVE-2025-49223: Naver Billboard.js RCE Vulnerability

CVE-2025-49223 Overview

A critical prototype pollution vulnerability has been identified in billboard.js, a popular JavaScript charting library developed by Naver. Versions prior to 3.15.1 contain a flaw in the generate function that allows attackers to inject arbitrary properties into JavaScript object prototypes. This vulnerability can be exploited to achieve arbitrary code execution or cause a Denial of Service (DoS) condition on affected systems.

Critical Impact

Attackers can exploit this prototype pollution vulnerability to execute arbitrary code or cause denial of service by injecting malicious properties through the vulnerable generate function in billboard.js.

Affected Products

• Naver billboard.js versions prior to 3.15.1

Discovery Timeline

• 2025-06-04 - CVE-2025-49223 published to NVD
• 2025-06-06 - Last updated in NVD database

Technical Details for CVE-2025-49223

Vulnerability Analysis

This vulnerability is classified under CWE-1321 (Improperly Controlled Modification of Object Prototype Attributes), commonly known as prototype pollution. The flaw resides in the generate function within billboard.js, which fails to properly validate and sanitize user-controlled input before using it to modify object properties.

In JavaScript, prototype pollution occurs when an attacker can modify the prototype of base objects like Object.prototype. Since almost all JavaScript objects inherit from Object.prototype, any properties added to it become accessible on all objects throughout the application. This can lead to severe consequences including arbitrary code execution, security control bypasses, and application crashes.

The vulnerability allows unauthenticated remote attackers to exploit the application without any user interaction, making it particularly dangerous for web applications that use billboard.js for data visualization.

Root Cause

The root cause of CVE-2025-49223 lies in the insufficient input validation within the generate function of billboard.js. The function processes configuration objects without adequately checking for dangerous property names such as __proto__, constructor, or prototype. When user-controlled data flows into this function, attackers can craft malicious payloads that pollute the JavaScript object prototype chain.

This type of vulnerability typically emerges when deep merge or recursive object assignment operations are performed without proper safeguards against prototype-polluting properties.

Attack Vector

The attack exploits billboard.js through network-accessible vectors, requiring no authentication or user interaction. An attacker can craft a malicious chart configuration object containing prototype-polluting properties and pass it to the vulnerable generate function.

When the application processes this malicious configuration, the injected properties propagate to Object.prototype, affecting all objects in the JavaScript runtime. Depending on how the application uses inherited properties, this can lead to:

• Arbitrary code execution through polluted properties that are later evaluated or executed
• Denial of service by corrupting critical application objects or causing unexpected exceptions
• Security control bypasses by overwriting authentication or authorization-related properties

Detection Methods for CVE-2025-49223

Indicators of Compromise

• Unexpected properties appearing on JavaScript objects that were not explicitly defined
• Application errors or crashes related to prototype chain corruption
• Unusual chart configuration payloads containing __proto__, constructor, or prototype keys
• Web application firewall logs showing attempts to inject prototype pollution payloads

Detection Strategies

• Monitor web application logs for incoming requests containing prototype pollution indicators such as __proto__ or constructor.prototype in JSON payloads
• Implement Content Security Policy (CSP) violations monitoring to detect unauthorized script execution
• Deploy runtime application self-protection (RASP) solutions that can detect prototype pollution attempts
• Use static analysis tools to identify vulnerable billboard.js versions in your codebase

Monitoring Recommendations

• Set up dependency scanning in CI/CD pipelines to flag billboard.js versions below 3.15.1
• Enable verbose logging for JavaScript errors that may indicate prototype chain corruption
• Monitor for unusual application behavior patterns that could indicate exploitation attempts
• Implement Software Composition Analysis (SCA) to continuously track vulnerable library versions

How to Mitigate CVE-2025-49223

Immediate Actions Required

• Update billboard.js to version 3.15.1 or later immediately
• Audit all applications using billboard.js to identify vulnerable instances
• Review application logs for any signs of exploitation attempts
• Implement input validation to filter prototype-polluting properties from user-controlled data

Patch Information

The vulnerability has been addressed in billboard.js version 3.15.1. Organizations using affected versions should upgrade to this version or later as soon as possible. For detailed information about the security fix, refer to the Naver CVE-2025-49223 Detail page.

Workarounds

• Implement server-side input sanitization to strip dangerous property names like __proto__, constructor, and prototype from configuration objects before passing them to billboard.js
• Use Object.freeze(Object.prototype) in your application to prevent prototype modifications (note: this may cause compatibility issues with some libraries)
• Deploy a Web Application Firewall (WAF) with rules to block requests containing prototype pollution payloads
• Consider using object creation patterns like Object.create(null) for configuration objects to avoid prototype chain inheritance

# Update billboard.js to the patched version
npm update billboard.js@3.15.1

# Verify the installed version
npm list billboard.js