I Almost Hacked Myself: Hilarious (and Painful) Lessons in Node.js Security

Fellow code wranglers. 🖖 Let’s get real for a second—Node.js is like that insanely cool, super fast sports car you’ve always dreamed of driving. But let’s not kid ourselves: if you’re not careful, you’ll crash it spectacularly. Been there, done that, and oh boy, do I have stories to tell.

So grab a coffee (or energy drink, I don’t judge), and let’s talk about Node.js security best practices—a.k.a., “how to not accidentally become the hacker you fear.” And before you roll your eyes thinking this is another dry checklist, let me assure you, this is the real stuff, hard-earned from years of trial, error, and facepalms. Let’s dive in.

The Time I Got Hacked (By Myself)

Picture this: I was a starry-eyed junior dev working on my first big project. The app? A snazzy to-do list (don’t laugh—baby steps). I was feeling unstoppable, tossing in dependencies left and right like toppings on a pizza. Need some authentication? Boom—jsonwebtoken. Database? Easy—MongoDB.

What I didn’t think about was this little gem:

const jwt = require('jsonwebtoken');
const token = jwt.sign({ userId: 123 }, 'supersecret');

“Supersecret”? More like “superstupid.” 🙃 Turns out, hardcoding your secrets in your codebase is a bit like leaving your house key under the doormat. Someone got into my app during a hackathon, and let’s just say they didn’t need a crowbar to steal all my user data. Lesson learned.

Fix: Always, always use environment variables for your sensitive stuff. Tools like dotenv are your friends:

require('dotenv').config();
const token = jwt.sign({ userId: 123 }, process.env.JWT_SECRET);

Easy, right? If only I’d known that before my repo got roasted in front of my team.

Dependency Roulette: The Silent Killer

Fast forward a year—I’m a bit older, a smidge wiser, and working on a shiny new API for a client. One day, I wake up to a Slack message from my PM: “Hey, why is our app mining Bitcoin?”

😳

Turns out, one of the npm packages I’d blindly installed had been compromised. (Shoutout to event-stream for teaching me about supply chain attacks the hard way.) The real kicker? I wasn’t even using half the dependencies I’d installed. I’d just copy-pasted my way into a potential data breach.

Fix:

1. Audit your dependencies regularly. Use tools like npm audit or snyk to catch vulnerabilities.
2. Don’t install random stuff. If you don’t know what a package does, don’t touch it.
3. Lock it down with package-lock.json. It’s not just there to annoy you during code reviews.

Sanitize Like Your App Depends On It (Because It Does)

Here’s a fun fact: the first time I got hit with an SQL injection attack, I thought, “Wait, isn’t that only for SQL databases?” Spoiler: no. MongoDB isn’t immune to injection attacks either. One little $where operator later, and boom—my database was doing things it definitely shouldn’t have been doing.

How did this happen? I was naively accepting user input without validation. Classic rookie move.

const user = await User.findOne({ username: req.body.username });

Harmless, right? WRONG. Someone sent in { "$where": "1 == 1" } as the username, and my entire user collection was on display like a Black Friday sale.

Fix:
Use libraries like mongoose and always validate your inputs. Bonus points if you sanitize them too:

const user = await User.findOne({ username: sanitize(req.body.username) });

Also, never forget the holy trinity:

1. Validate inputs.
2. Escape outputs.
3. Use parameterized queries.

The “Oops, Forgot to Limit” Saga

This one still haunts me. I was working on an endpoint that returned a list of products. Simple, right?

const products = await Product.find({});
res.json(products);

What I forgot was that there were over 10,000 products in the database. A single request took the entire app down faster than you can say “rate limit.” The client wasn’t thrilled, to say the least.

Fix: Always set sensible limits and pagination. Here’s a basic example:

const page = req.query.page || 1;
const limit = 10;
const products = await Product.find({})
  .skip((page - 1) * limit)
  .limit(limit);
res.json(products);

Your database will thank you. Your users will thank you. And your PM might actually stop glaring at you during standups.

It’s Not Just About Code—Secure Your Server

So, I finally got the hang of writing secure Node.js code, but then came the Great DDoS Incident of 2020™. Someone flooded my app with requests, and my server folded like a cheap lawn chair. Turns out, even the best code can’t save you from a poorly configured server.

Fix:

1. Use a reverse proxy like Nginx to handle traffic.
2. Enable rate limiting with middleware like express-rate-limit:

   const rateLimit = require('express-rate-limit');
   const limiter = rateLimit({
     windowMs: 15 * 60 * 1000, // 15 minutes
     max: 100, // limit each IP to 100 requests per windowMs
   });
   app.use(limiter);

3. Protect your server with a firewall. If you’re on AWS or GCP, take advantage of their built-in tools.

Closing Thoughts (and a Bit of Self-Reflection)

If there’s one thing I’ve learned as a Node.js dev, it’s this: security isn’t a one-and-done deal. It’s a process. A mindset. Heck, it’s a way of life. (Okay, maybe not that dramatic, but you get the idea.)

And let’s be real—no one gets it perfect the first time. I’ve made my fair share of mistakes, and I’ll probably make a few more. But the key is to keep learning, keep improving, and keep your server logs handy for when (not if) things go wrong.

So, fellow devs, let’s write better code, secure our apps, and maybe—just maybe—avoid those 3 a.m. “why is the server down?” wake-up calls.

Catch you in the next post! 🚀

Let me know what you think! Have you ever made a facepalm-worthy security mistake? Drop it in the comments and let’s commiserate.