NoSQL Injection attack in Node.js

Introduction:

NoSQL injection is a type of security vulnerability that occurs in web applications that use NoSQL databases, such as MongoDB, and is caused by improper input validation. The vulnerability allows attackers to inject malicious code into the queries that an application sends to the database, leading to unauthorized data access or data modification.

In Node.js, NoSQL injection attacks can occur when user input is not properly sanitized or validated before being used in a database query. Here is an example of how a NoSQL injection vulnerability can occur in a Node.js application using MongoDB:

const express = require('express');
const app = express();
const MongoClient = require('mongodb').MongoClient;

const url = 'mongodb://localhost:27017';
const dbName = 'test';

app.get('/search', (req, res) => {
    const query = req.query.q;
    MongoClient.connect(url, function(err, client) {
        if (err) throw err;
        const db = client.db(dbName);
        db.collection('items').find({ name: query }).toArray(function(err, result) {
            if (err) throw err;
            res.json(result);
            client.close();
        });
    });
});

app.listen(3000, () => {
    console.log('Server started on port 3000');
});

In this example, we have an endpoint /search that allows a user to search for data in a MongoDB collection by passing a query parameter q. The code uses the find() function to search for items with a matching name field in the items collection.

However, the code is vulnerable to NoSQL injection attacks because it uses the user input directly in the query without proper validation or sanitization. An attacker could send a malicious query like { $ne: null }, which would result in the following query being executed on the database:

db.collection('items').find({ name: { $ne: null } }).toArray(function(err, result) {
    // ...
});

This would return all items in the items collection, even if their name field is null, which is likely not the intended behaviour.

To prevent NoSQL injection vulnerabilities in Node.js, it’s important to properly validate and sanitize user input before using it in a database query. Here is an example of how to prevent NoSQL injection vulnerabilities in the above example:

const express = require('express');
const app = express();
const MongoClient = require('mongodb').MongoClient;

const url = 'mongodb://localhost:27017';
const dbName = 'test';

app.get('/search', (req, res) => {
    const query = req.query.q;
    MongoClient.connect(url, function(err, client) {
        if (err) throw err;
        const db = client.db(dbName);
        db.collection('items').find({ name: { $regex: new RegExp(`^${query}$`, 'i') } }).toArray(function(err, result) {
            if (err) throw err;
            res.json(result);
            client.close();
        });
    });
});

app.listen(3000, () => {
    console.log('Server started on port 3000');
});

In this modified example, we use the $regex operator to perform a case-insensitive regular expression search for items with a matching name field. The regular expression is constructed using the user input and is properly sanitized using the RegExp constructor to ensure that it only matches the exact input string and nothing else. This prevents NoSQL injection attacks by ensuring that the user input is only used as intended and cannot modify the query unexpectedly.

, , , , ,

Related posts

Latest posts

Leave a Comment

Leave a Reply

Your email address will not be published. Required fields are marked *

Please disable your adblocker or whitelist this site!

How to whitelist website on AdBlocker?

How to whitelist website on AdBlocker?

  1. 1 Click on the AdBlock Plus icon on the top right corner of your browser
  2. 2 Click on "Enabled on this site" from the AdBlock Plus option
  3. 3 Refresh the page and start browsing the site