Security testing
Most testing, functional or otherwise, checks that software behaves correctly under normal, well-behaved conditions. Security testing checks what happens under adversarial ones, deliberately malformed input, a login form fed something it was never designed to handle, a request crafted to see whether an access control actually holds up. It's less concerned with whether a feature works and more concerned with whether it can be tricked into doing something it shouldn't.
That work generally falls into a few recognizable categories. Vulnerability scanning uses automated tools to check for known weaknesses, like a dependency with a published, catalogued vulnerability. Penetration testing goes further, with a person, or a team, actively trying to break in or bypass a control the way a real attacker would, which can surface issues an automated scan was never built to look for. Static and dynamic analysis scan source code or a running application for common flaws, like SQL injection or cross-site scripting. Authentication and authorization testing checks something more specific: whether access controls actually enforce who is allowed to see or do what, not just whether a login screen exists.
Increasingly, this work happens continuously rather than as a single audit before launch. A vulnerability caught in the same pull request that introduced it is far cheaper and safer to fix than one discovered months later in production, after other code has been built on top of it, which is why automated scanning has become a routine part of many CI/CD pipelines rather than a step reserved for right before release.
Common approaches
- Vulnerability scanning, using automated tools to check for known weaknesses, like an outdated dependency with a published vulnerability.
- Penetration testing, where a person deliberately tries to break into or bypass the system the way a real attacker would.
- Static and dynamic analysis, scanning source code or a running application for common flaws like SQL injection or cross-site scripting.
- Authentication and authorization testing, checking whether access controls actually enforce who is allowed to see or do what.
Where it shows up
- Running automated vulnerability scans as part of a CI/CD pipeline, catching a known weakness before a change even merges.
- Commissioning a penetration test ahead of a major release or as a periodic check on a production system.
- Verifying that one user genuinely can't access another user's data by changing an ID in a request.
- Checking that a login form resists common attacks, like brute-forcing a password or injecting malicious input.
Benefits and challenges
| Benefit | Challenge |
|---|---|
| Catches a vulnerability before it's exploited, rather than finding out from an actual breach. | Needs specialized knowledge, a general QA background doesn't automatically cover how to think like an attacker. |
| Automated scanning can run continuously and catch known issues, like an outdated dependency, with very little ongoing effort. | Automated tools mostly catch known, previously catalogued issues, a genuinely novel attack often needs a person actively looking for it. |
| Builds trust with users and customers who are handing over real data to the application. | Security is never fully finished, new vulnerabilities get discovered in existing dependencies on an ongoing basis, not just at launch. |
Frequently asked questions
What's the difference between vulnerability scanning and penetration testing?
Vulnerability scanning is automated, checking a system against a database of known weaknesses, like outdated software with a published vulnerability. Penetration testing is done by a person, actively trying to break in or bypass a control the way a real attacker would, which can catch issues an automated scan was never built to look for.
Should security testing happen before launch or continuously?
Continuously, ideally alongside every change rather than as a single audit before a release. A vulnerability caught in the same pull request that introduced it is far cheaper and safer to fix than one discovered months later in production, after other code has been built on top of it.
Is security testing only relevant for large applications?
No. Any application handling user data, accepting input, or requiring a login has some surface an attacker could target, regardless of size. Smaller applications often get less security attention specifically because they're assumed to be lower risk, which is part of why they end up targeted.
How Klarent helps
Klarent's AI agents focus on functional and regression coverage across an application's user flows, such as the claims journeys in insurance application testing, working alongside dedicated security testing tools and practices rather than replacing the specialized scanning and penetration testing a real security program needs.