Should we buy web app pen-testing tools and run tests ourselves, or hire an external firm?

The biggest blind spot of automated tools is parameter tampering and context-dependent workflows. A scanner can't catch someone skipping steps in a multi-step checkout flow to trigger a completion. Let your dev team run the scans to clean up low-level stuff like SQLi and XSS, but authorization checks strictly require a human eye.

Our 3-person team tried doing this exact thing last year. We ran a popular open-source scanner and it dumped 184 security alerts on us. Our engineer spent two full weeks digging through them, and 168 turned out to be false alarms. The cost of two weeks of lost engineering time ended up being way higher than what we would have paid an outside tester.

Be careful when outsourcing this too. Plenty of so-called security firms out there claiming to do tests for 2,000-3,000 dollars literally just run the exact same open-source scanner you'd set up, slap the output into a template with their logo, and hand it over as a report. If you're going to hire someone, make sure the contract explicitly states that manual business logic testing is included.

Correction: I misremembered the figure, it was a bit lower.

Take it step by step: first integrate open-source static code analysis tools into your CI/CD pipeline. That cleans things up at zero cost. Next, talk openly with the client and ask what minimum certification or accreditation standard they'll accept. Sometimes narrowing the scope down to just the external web-facing surface directly cuts the quote in half.

Quick question: if we put a solid cloud WAF in front of our web app to filter traffic wouldn't that eliminate the need for penetration tests altogether? tbh don't clients consider that enough?

A firewall is the security guard at the door; a pentest is the structural engineer inspecting the building for architectural flaws. A firewall blocks known attack patterns, but it can't detect design flaws or privilege escalation issues baked into your application. Clients want to see how secure the code behind the wall is, so a firewall won't cut it as a substitute for a report.

We went through the exact same shock on our first enterprise sale; our hands were shaking when a 6,000 dollar quote came in... We were honest with the client about being an early-stage startup, narrowed the scope down to the critical endpoints, hired an independent freelance security pro for 2,500 dollars and got the sign-off report. I mean keep the lines of communication open, that's my advice.

enterprise procurement will never accept your in-house report unfortunately. the whole point of that report is having an independent third party put their stamp on it. just use those tools for internal cleanup imo otherwise you're wasting your time.

Looking at it as a process the picture changes. The answer varies greatly by industry; there is no one-size-fits-all rule.

Of course it varies if your situation is different.

I agree with this. The real issue isn't the number but what it's based on.

This is my opinion, I'm not claiming it's absolute truth.

How did you solve this? The biggest time-waster for us was not knowing who had the final say.

If you post the result here, it will help others too.

Let me summarize what's been said so far. Just because everyone does it doesn't mean it's right.

Just a heads-up. Your time to detect an issue directly determines its cost.

Correct me if I'm wrong.

I went through the same thing.

Same here.

Following. An automated scan report is not the same as a penetration test.

I'm curious too. If you get three different answers on a topic, the question was asked wrong.

Good luck with that.

I'm a small business, let me explain from my side. If you don't write this down from the start, it leads to arguments later.