False positives in application security negatively impact the work of cybersecurity experts, developers, and the entire business. This post explains false positives in the context of Web AppSec, demonstrates why less advanced web security tools are prone to false positives, and shows how Invicti’s web application security scanner addresses the problem of false positives through demonstrable accuracy.
What is a false positive in cybersecurity?
A false positive is like a false alarm when your home alarm goes off, but there is no burglar. In web application security, a false positive is when a web application security scanner indicates that your website has a vulnerability, such as SQL injection either cross-site scripting (XSS), but in reality, there is nothing to fix. In other areas of cybersecurity, false positives can literally be false alarms that security professionals are endlessly hunting for nonexistent cyberattacks.
It’s no wonder that false positives are a leading cause of burnout among security professionals.
false negatives in web application security are vulnerabilities that exist but were not found by a vulnerability scanner. Because you need to know about the security vulnerability in advance, the concept of false negatives only makes sense in artificial test environments for evaluation or benchmarking; consult our blog post about false negatives Learn more.
False positives make web application security unaffordable
All AppSec work needs a good vulnerability scanner, either as a stand-alone Dynamic Application Security Testing (DAST) tool or as an aid for manual penetration testing. In both cases, having a high number of false positives makes protecting your web assets time consuming and expensive.
It is AppSec best practice to build security test automation into your web development process and test as early as possible. To keep up with software innovation, you should automatically feed vulnerability scan results into the developer workflow, but this won’t work if they include false positives. If your teams can’t trust the scanner, your security experts will have to manually validate each scan result, wasting time and money and slowing down the entire development process. In a typical business environment, that gets expensive quickly: to the tune of $500K a year.
In penetration tests, false positives are no less damaging. When inundated with false positives from a low-quality scanner, security experts will spend valuable time investigating minor issues instead of focusing on vulnerabilities that really need their expertise. This can make security testing seem too expensive for some organizations, resulting in incomplete security coverage that puts them at risk of cyberattacks, but makes it worse.
False positives hide vulnerabilities in real web applications
Humans tend to start ignoring false alarms pretty quickly, and AppSec pros are no exception. If a web application security scanner detects 200 cross-site scripting vulnerabilities and a security engineer or penetration tester finds that the first 20 variants are false positives, he or she would likely assume that all XSS reports are false positives. and ignore them.
False positives cause users to distrust all scan results by default and deal with common issues like noise. This creates a huge security risk, as real vulnerabilities can slip through testing and leave the door wide open for malicious hackers. And because they have been manually flagged as false positives, they could remain uncorrected and unreported for a long time, creating an even bigger security threat.
Investigating a false positive takes skill and time
Anytime a security engineer, penetration tester, or application developer needs to investigate a false-positive scan result, the effect is only as good as that person’s skill, experience, and perseverance. If users can’t trust the results of their scans, they’ll naturally assume that anything they can’t find or manually test must be a false positive.
In fact, state-of-the-art vulnerability scanners incorporate many years of AppSec research and development, so they can (and do) report vulnerabilities that a specific user might not or might not be able to check for. If these advanced vulnerabilities are ruled out as false positives, they may never be fixed, again leaving the web application at risk of attack.
Trusting your AppSec solution becomes even more critical with non-interactive web assets like APIs, where investigating a vulnerability report often requires dedicated tools and skills. False positives in API scan results can be a real deal breaker, forcing developers to waste valuable time checking their source code for non-existent defects. As release deadlines approach, many development teams will be tempted to bypass these pesky security checks, and research confirms that even 70% of them do exactly that..
The hidden costs of false positives in modern AppSec
Any serious web application security program needs a vulnerability scanner. No matter where and how you use it, the accuracy and real-life effectiveness of your chosen solution can make or break your AppSec efforts, so this decision requires a lot more care than simply checking a box. Whether you rely on web vulnerability scanning for all your dynamic security testing or combine it with manual penetration testsinaccurate results riddled with false positives can jeopardize your teams’ hard work, affect your security posture, and actually cost you money.
A high-quality DAST solution integrated into your software development workflow, especially in modern DevSecOps shops, can serve as a stand-alone tool for finding real issues and tracking down their fix with very little hands-on interaction. An inadequate scanner, on the other hand, will always require your security engineers to spend precious time manually verifying the scan results, giving developers guidance for the fix, and retesting the fixes. Add to this the time the developer spends investigating false alarms and getting actionable insights from the security team, and you’re paying for hundreds of hours a year spent manually validating low-quality vulnerability reports.
Automated scanners will never replace professional penetration testers, and a robust AppSec program should combine both. However, a good tool can make manual testing faster and more cost-effective, allowing testers to focus on vulnerabilities that cannot be detected automatically, while a bad tool will make the whole process slower and more expensive. . Similarly, if you run a bug bounty program, an accurate vulnerability scanner will allow you to internally identify and fix most common security flaws without paying bounties for trivial bugs. As ethical hackers focus on more advanced attack pathways, you get better value for money and better protection against real threats.
Demonstrable Accuracy: Invicti Evidence-Based Scanning
Virtually all application security testing tool vendors will claim “fewer false positives” or even “zero false positives”, but any discussion of the number of false positives is really answering the wrong question. Even having zero false positives isn’t good on its own: you could get zero false positives simply because the scanner missed something you weren’t sure about. So a better question is: Can the solution find real, exploitable vulnerabilities and deliver truly positive results for developers to fix? Invicti evidence-based scanning technology was designed to provide the answer.
The only way to prove that a vulnerability is exploitable is to actually exploit it and then demonstrate how it was done. Invicti builds on more than a decade of web security research and development to deliver a web application security solution that can find, safely exploit, and confidently confirm the vast majority of direct hit vulnerabilities: more than 94% of them, to be exact. By providing clear proof of exploitation of the security flaws that really matter, Invicti avoids pointless arguments about who has fewer false positives and focuses squarely on making your web applications more secure.
Read our full white paper: False Positives in Web Application Security: Meeting the Challenge