CVE-2025-57328: Toggle-array Prototype Pollution Vulnerability

CVE-2025-57328 Overview

CVE-2025-57328 is a Prototype Pollution vulnerability affecting the toggle-array npm package, a utility designed to enable a property on an object at a specified index while disabling the property on all other objects. The vulnerability exists in the enable and disable functions of toggle-array version 1.0.1 and earlier, allowing attackers to inject properties onto Object.prototype via crafted payloads. This can result in denial of service (DoS) as a minimum consequence, with potential for broader application impact depending on downstream usage patterns.

Critical Impact

Attackers can pollute JavaScript Object prototypes via the enable and disable functions, causing denial of service and potentially enabling further exploitation depending on application context.

Affected Products

• jonschlinkert toggle-array v1.0.1 and earlier
• Node.js applications using toggle-array package
• Any application importing toggle-array as a dependency

Discovery Timeline

• 2025-09-24 - CVE-2025-57328 published to NVD
• 2025-10-20 - Last updated in NVD database

Technical Details for CVE-2025-57328

Vulnerability Analysis

Prototype Pollution is a JavaScript-specific vulnerability class where attackers can inject properties into the base Object.prototype. Since nearly all JavaScript objects inherit from Object.prototype, polluted properties propagate throughout the application's object hierarchy. In the case of toggle-array, the enable and disable functions do not properly validate or sanitize input indices, allowing attackers to supply specially crafted payloads that traverse the prototype chain.

When a malicious index such as __proto__ or constructor.prototype is passed to these functions, the attacker can inject arbitrary properties into the global object prototype. This pollution persists for the lifetime of the application process and affects all subsequently created objects.

Root Cause

The root cause is insufficient input validation within the enable and disable functions. These functions fail to check whether the supplied index corresponds to special JavaScript properties like __proto__, constructor, or prototype. Without proper sanitization, the functions directly access and modify object properties using attacker-controlled keys, enabling prototype chain traversal and pollution.

The vulnerability falls under CWE-1321 (Improperly Controlled Modification of Object Prototype Attributes), which describes scenarios where untrusted input is used to modify object prototypes without proper validation.

Attack Vector

The attack is network-accessible, requiring no authentication or user interaction. An attacker can exploit this vulnerability by sending crafted input to any application endpoint that passes user-controlled data to the toggle-arrayenable or disable functions.

The exploitation mechanism involves passing a malicious index value (such as __proto__) along with a property name and value. When processed by the vulnerable functions, this payload modifies Object.prototype, injecting attacker-controlled properties that affect all objects in the application.

For technical details on the exploitation mechanism, refer to the GitHub PoC Repository which contains proof-of-concept code demonstrating the vulnerability.

Detection Methods for CVE-2025-57328

Indicators of Compromise

• Unexpected properties appearing on objects that were not explicitly defined
• Application crashes or hangs related to infinite loops or unexpected object states
• Log entries showing unusual index values containing __proto__, constructor, or prototype in toggle-array function calls
• Denial of service conditions in Node.js applications using toggle-array

Detection Strategies

• Implement runtime monitoring to detect prototype pollution attempts by checking for modifications to Object.prototype
• Use static analysis tools to identify usage of toggle-array v1.0.1 or earlier in your dependency tree
• Deploy Web Application Firewalls (WAF) with rules to detect payloads containing prototype pollution signatures
• Implement application-level logging for toggle-array function calls with validation of index parameters

Monitoring Recommendations

• Monitor application dependency manifests (package.json, package-lock.json) for vulnerable toggle-array versions
• Set up alerts for unusual application behavior patterns indicative of prototype pollution
• Implement SentinelOne Singularity XDR for real-time detection of exploitation attempts targeting Node.js applications
• Review application logs for repeated errors or exceptions originating from toggle-array module calls

How to Mitigate CVE-2025-57328

Immediate Actions Required

• Audit your applications to identify any usage of toggle-array v1.0.1 or earlier
• Remove or replace toggle-array with a non-vulnerable alternative if no patch is available
• Implement input validation to sanitize any user-controlled data before passing to toggle-array functions
• Consider using Object.create(null) for objects that should not inherit from Object.prototype

Patch Information

At the time of publication, check the jonschlinkert toggle-array repository for updated versions that address this vulnerability. If no official patch is available, consider the workarounds below or replace the package with a secure alternative.

Workarounds

• Implement wrapper functions that validate index parameters before calling toggle-array functions, rejecting values like __proto__, constructor, and prototype
• Use Object.freeze(Object.prototype) at application startup to prevent prototype modifications (note: this may break some libraries)
• Replace toggle-array with custom implementation that includes proper input validation
• Apply the principle of least privilege to limit the impact of potential prototype pollution

# Check if your project uses vulnerable toggle-array version
npm ls toggle-array

# If vulnerable, attempt to update or remove
npm update toggle-array

# Alternatively, audit all dependencies for prototype pollution vulnerabilities
npm audit