The Security Mistakes We Keep Finding in Web Applications
Every application is different, but the weak spots rarely are. After testing a lot of web applications, you start to see the same handful of problems turn up again and again. None of them are exotic, and most are easy to fix once you know they are there. Here are the ones we find most often, and what to do about each one.
Trusting input that should never be trusted
The oldest trap in the book, and still the most common. If your application takes something a user typed and hands it straight to a database or a page without checking it, you have handed the keys over too. Treat everything that comes from outside as suspect, validate it, and never build queries by gluing strings together.
Access controls that are easy to walk around
We often find that a screen is hidden rather than protected. If a normal user can reach an admin page just by changing a number in the address bar, the lock was only ever painted on. Check permissions on the server for every request, not just by hiding buttons in the browser. The browser is not where your security lives.
Secrets sitting in plain sight
Passwords, keys and tokens have a habit of ending up where they should not: hard coded in the app, committed to the repository, or printed into logs. Anyone who gets a peek then gets the crown jewels. Keep secrets out of code, rotate them, and make sure they never land in a log file.
Old libraries nobody got around to updating
Modern apps lean on a lot of third party code, and a fair bit of it is out of date. Attackers love this because the weaknesses are already public and easy to look up. Keep an inventory of what you depend on, patch it regularly, and watch for alerts on the pieces you use.
Error messages that say far too much
A stack trace or a detailed database error splashed across the screen is a gift to anyone poking at your app. It quietly explains how the thing is built. Show users a friendly, vague message, and keep the useful detail in your own logs where only your team can see it.
The fix is usually simpler than the worry
Here is the good news. Almost everything on this list is cheap to fix once you know it is there, and a single test will usually surface the lot. The hard part is looking. If you would like a fresh set of eyes on your web application, that is exactly what we do. Reach out and we can take a look.
