Koa Mongoose Sanitize
Koa.js middleware which sanitizes user-supplied data to prevent MongoDB Operator Injection.
Inspired by mongo-sanitize and based on the pure logic of express-mongo-sanitize.
Installation
# npm
$ npm install koa-mongo-sanitize
# yarn
$ yarn add koa-mongo-sanitizeUsage
This is a practical example of how to use.
const Koa = require('koa');
const Router = require('koa-router');
const bodyParser = require('koa-bodyparser');
const mongoSanitize = require('koa-mongo-sanitize');
const app = new Koa();
app.use(bodyParser());
// To remove data, use:
app.use(mongoSanitize());
// Or, to replace prohibited characters with _, use:
app.use(mongoSanitize({
replaceWith: '_'
}))What?
This module searches for any keys in objects that begin with a $ sign or contain a ., from ctx.request.body, ctx.request.query or ctx.request.params. It can then either:
- completely remove these keys and associated data from the object, or
- replace the prohibited characters with another allowed character.
The behaviour is governed by the passed option, replaceWith. Set this option to have the sanitizer replace the prohibited characters with the character passed in.
See the spec file for more examples.
Why?
Object keys starting with a $ or containing a . are reserved for use by MongoDB as operators. Without this sanitization, malicious users could send an object containing a $ operator, or including a ., which could change the context of a database operation. Most notorious is the $where operator, which can execute arbitrary JavaScript on the database.
The best way to prevent this is to sanitize the received data, and remove any offending keys, or replace the characters with a 'safe' one.
Note
You can use pure mongo sanitize logic.
const { sanitize } = require('koa-mongo-sanitize');
// do any think you want.