How Secure Is Your App? 7 Vulnerabilities You Should Fix Today

Have you ever had that weird, uneasy feeling when you lock the front door but can’t remember if you actually turned the key? You double back just to check—because if you’re wrong, it could cost you.

Now think about your app.

You’ve spent weeks—maybe months—bringing it to life. Late nights. Debugging marathons. Proud moments when it finally worked. But somewhere in the rush to launch, there’s a question quietly knocking at the back of your mind:

“Is this thing secure?”

If you’ve ever wondered that—or even if you haven’t yet—you’re not alone. The truth is, security tends to take a backseat until something goes wrong.

So let’s slow down, take a breath, and walk through seven common vulnerabilities that could be quietly putting your app at risk. No judgment, no jargon overload—just real talk and practical steps you can take today.

1. Weak or Missing Authentication

Let’s start with something simple, but incredibly easy to overlook: how users log in.

If your app doesn’t have strong authentication controls, it’s like leaving the door cracked open with a “please don’t enter” sign.

What this looks like in real life:

Users do not need to confirm their email address in order to log in.
Passwords like "123456" or "password" are allowed.
There’s no rate limit on login attempts—meaning attackers can keep guessing forever.

What you can do:

Demand secure passwords (and assist users in creating them).
Add two-factor authentication (2FA). Even SMS is better than nothing.
Lock accounts after several failed attempts or introduce CAPTCHA.

Small changes here go a long way. It's like changing from a flimsy lock to a deadbolt.

2. Exposed APIs

APIs are like open windows to your app. They’re supposed to let the right things in and out. But if they’re exposed or misconfigured, they can let in more than you bargained for.

Imagine this:
You have a “Get User Info” API. A curious user modifies the user ID in the request and—oops—they now have access to someone else’s data.

What to do:

Always verify user permissions before showing or editing data.
Don’t rely on “hidden” URLs or app logic to protect sensitive actions.
Use API gateways or middleware to enforce access control rules.

You wouldn’t leave your home’s windows wide open at night. Treat your APIs with the same care.

3. Insecure Data Storage

Let’s say your app stores user preferences locally. Seems harmless, right? Now imagine it also stores login tokens, payment info, or medical records… unencrypted.

Here’s the scary part:
If a phone is lost, stolen, or even just jailbroken, all that data might be up for grabs.

What you should do:

Never store sensitive data unencrypted—on the device or your server.
Use secure storage tools (like Keychain for iOS or Keystore for Android).
Don’t store what you don’t need. Less data = less risk.

Your users trust you with their information. Let’s respect that trust.

4. Improper Error Handling

Have you ever seen a website crash and show a big white screen full of code? Those stack traces might look like gibberish to most people—but to a hacker, they’re a treasure map.

Real-world example:
An error message might accidentally reveal database names, server structure, or even file paths.

What you can do:

Show friendly, generic error messages to users (“Oops! Something went wrong.”)
Don’t leak system-level messages in your frontend or APIs.

Think of it this way: You don’t need to tell strangers how your alarm system works. Just let them know it’s there.

5. Unvalidated Inputs (A.K.A. The Classic Hack)

You’ve probably heard of SQL injection. Or maybe you haven’t, and that’s okay. The idea is simple:

If you accept user input (like a form field or a search bar) and don’t clean it up before using it in your app’s logic, bad things can happen.

For example:

A user types something sneaky into a field.
Your app runs it as code instead of treating it as plain text.
Suddenly, they’ve accessed or even deleted your database.

To avoid this:

Use prepared statements or parameterized queries for your database.
Escape output if you’re showing user-generated content (especially in HTML).

It’s not about paranoia. It’s about knowing that your app lives in the real world, and real people will try to break it.

6. Outdated Libraries or Frameworks

It’s easy to forget about the tools under the hood—especially when they’re working fine. But outdated libraries are one of the sneakiest sources of security holes.

Think of it like this:
Would you run your laptop without updates for three years? Probably not. But many apps do just that with their dependencies.

What you should do:

Regularly check your app’s dependencies for updates or known vulnerabilities.
Use tools like npm audit (for Node.js) or Snyk to scan for issues.
Automate security updates if possible.

Keeping your tools updated is like getting your car serviced before it breaks down on the highway.

7. No HTTPS (or Misconfigured HTTPS)

This one feels almost too obvious, but it’s still a problem on way too many apps.

If your app isn’t using HTTPS for all communication, your users’ data can be intercepted. Period.

Also important:
Just having HTTPS isn’t enough. If you don’t configure it correctly, attackers can still slip through.

What to do:

Get a valid SSL certificate (many are free via Let’s Encrypt).
Force HTTPS for all traffic.
Check for expired or misconfigured certificates regularly.

Think of HTTPS as the envelope around your letter. Without it, your message is just flapping around in the breeze.