What is application security testing? AST explained

August 17, 2024 • Resource
Posted by
Ash Donaldson
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An Application Security Test identifies vulnerabilities in your web application that could lead to the compromise or corruption of your data, or affect your application's availability. Finding these vulnerabilities before a real attacker does can help avoid impact to your users, and prevent reputational and possibly legal impacts for your business.

If you run a website or web application, application security testing should be a key test activity, both before your initial release, as well as regular checkups.

How does application testing work?

In an Application Security Test, the tester interacts directly with the web application server - circumventing any web browser protections - sending abnormal or malicious input, both manually and using automated tools. Any unexpected response from the web server is investigated further, as it may indicate a possible vulnerability; and, with the client's permission, the tester attempts to exploit the vulnerabilities to see what the impact could be. Common web application vulnerabilities include Cross-Site Scripting, SQL Injection, and Authorisation Bypass, all of which can lead to data breaches. In addition to identifying severe vulnerabilities that are fully exploitable, the test team also identifies best-practice violations, which might increase your risk.

A test can occur with the tester being given no help - a "black-box" test - to simulate a hacker on the internet. However, to get the most value out of an authorised test, giving the tester access to source code, configuration files, and maybe even the ability for them to run your application on their own system with a debugger attached, allows them to more quickly understand the behaviour of the application, ruling out false positives, and honing in on the real issues. The more visibility and control that the testing team has, the faster and more effective they can be in finding vulnerabilities.

How Tesserent can help

Tesserent offers a range of application security testing services including web application penetration testing, mobile application penetration testing, API penetration testing, secure code review, and other testing. Our methodology for testing is based on internal research, the Open Web Application Security Project (OWASP) methodology, and other respected test frameworks. Our experts utilise automated tools and finely honed manual techniques, gained through years of experience, to help build a better picture of your application security.


Written by Ash Donaldson

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