In the context of penetration (pen) testing, false positives are where the testing tools or methods identify a security vulnerability or issue that doesn’t actually exist. Essentially, a false alarm. This can happen for a few reasons, such as misconfigurations in the testing tools, incorrect assumptions, or environmental factors. False positives can lead to unnecessary follow-up actions and waste valuable time and resources, so it’s important to validate and verify any findings to ensure they’re genuine.

False negatives versus false positives in cybersecurity

‘False negatives’ are an obvious danger in security processes like penetration testing: by classing a real vulnerability as benign, the risks are obvious. False positives pose a different problem. Like a health scare that turns out to be nothing serious, it may be tempting to greet false positives with relief – but in cybersecurity, it’s not quite so simple. When we mistakenly see a malicious danger or threat in our networks or systems, this can mean wasted time and resources that could be better spent on dealing with actual threats.

What are the risks with false positives?

The article discusses the significant challenges posed by false positives in threat hunting. False positives can lead to alert fatigue, where security teams become overwhelmed and may start ignoring alerts, including legitimate ones. This can result in genuine threats being overlooked. Additionally, false positives consume valuable time and resources that could be better spent addressing actual security issues. They also erode trust in security tools and processes, leading to poor decision-making and a lack of confidence in the organization’s cybersecurity capabilities.

Frustrations for IT teams

False positives in penetration testing can be problematic and frustrating for IT teams for several reasons:

1. Alert fatigue: This is where security teams become numb to the many false positives they’re ‘alerted’ to investigate. The biggest issue with alert fatigue is that a security team accidentally misses or ignores a serious risk – as they’re become to desensitized to constant alerts that often end up being false positives.  

2. Wasted time and resources: IT teams have to spend time and effort investigating and validating each reported issue, even if it turns out to be a false positive. False positives can skew the prioritization of security tasks. Teams might focus on addressing non-existent issues while more critical vulnerabilities go unnoticed.
3. Reduced trust in tools: If false positives occur frequently, IT teams may start to lose trust in the accuracy and reliability of the penetration testing tools and methods they are using. This can lead to a reluctance to use these tools, potentially missing real vulnerabilities. Verifying and managing false positives can be overwhelming, especially for teams that are already stretched thin. This can lead to burnout and decreased morale.

Why are your pen testing tools getting false positives?

There can be many factors behind false positives. For example, misconfigured or overzealous security settings, limitations in detection algorithms, or outdated threat signatures. Flaws in testing tools that can lead to more false positives include:

1. Inaccurate detection algorithms: Some tools may use detection algorithms that are not finely tuned, leading to overly broad or incorrect identifications of vulnerabilities. For example, a tool might flag a configuration as insecure when it is actually a known and accepted practice.
2. Outdated signatures: Penetration testing tools often rely on a database of known vulnerabilities and attack patterns. If these databases are not regularly updated, the tools may flag issues that have already been patched or are no longer relevant.
3. Over-sensitivity: Some tools are set to be overly sensitive to detect as many potential issues as possible. While this can help catch real vulnerabilities, it also increases the likelihood of false positives. If a tool is not properly configured to exclude certain known good configurations, it might flag them as issues.
4. Lack of context: Many automated tools lack the context to understand the specific environment and configurations of the systems they are testing. Without this context, they may incorrectly flag benign configurations as vulnerabilities.
5. False Assumptions: Tools may make assumptions about the environment or the way certain services are configured. If these assumptions are incorrect, it can lead to false positives. If the IT team provides incorrect or incomplete information to the testing tools, it can also lead to false positives.

Specific false positive risks with web applications

False positives in web application penetration testing can be particularly problematic due to the complex and dynamic nature of web applications.

1. Dynamic content: Web applications often generate dynamic content, which can change based on user input or other factors. Testing tools might misinterpret this dynamic content as a security issue, leading to false positives in pen testing.
2. Session management: Web applications rely heavily on session management techniques like cookies and tokens. Testing tools might flag legitimate session management practices as potential vulnerabilities if they don’t fully understand the application’s session handling mechanisms.
3. Input validation: Web applications often have complex input validation rules. Testing tools might incorrectly identify valid input as malicious or suspicious, especially if the validation rules are not well-documented or understood by the tool.
4. Custom frameworks and libraries: Many web applications use custom frameworks or libraries. Testing tools that are not familiar with these custom components might generate false positives by misinterpreting their behavior.
5. Rate limiting and throttling: Web applications often implement rate limiting and throttling to prevent abuse. Testing tools might trigger these mechanisms, leading to false positives if the tool interprets the rate limiting as a security issue.
6. Captcha and anti-bot mechanisms: Web applications frequently use CAPTCHAs and other anti-bot mechanisms to prevent automated attacks. Testing tools might be flagged by these mechanisms, leading to false positives if the tool interprets the anti-bot response as a security issue.
7. Content security policies (CSP): Web applications often use Content Security Policies to enhance security. Testing tools might misinterpret CSP settings as restrictive or problematic, leading to false positives.
8. Third-party integrations: Web applications often integrate with third-party services. Testing tools might not fully understand these integrations and might flag legitimate interactions as potential vulnerabilities.
9. False alerts from heuristics: Heuristic analysis in web application testing can be particularly prone to false positives. For example, a tool might flag a benign script as a potential XSS (Cross-Site Scripting) attack if it doesn’t fully understand the context in which the script is used.
10. Configuration and customization: Web applications are often highly configurable and customizable. Testing tools that do not account for these customizations might generate false positives by misinterpreting legitimate configurations as security issues.

How to reduce false positives when pen testing

Reducing false positives when penetration testing is crucial for maintaining the efficiency and effectiveness of your security efforts. Here are several strategies IT teams can use to minimize false positives:

1. Calibrate and configure tools:
   • Customize settings: Adjust the settings of your testing tools to match the specific environment and configurations of your web application. This includes setting thresholds for what is considered a vulnerability.
   • Exclude known good configurations: Configure the tools to exclude known good configurations and benign behaviors that are specific to your application.
2. Use context-aware testing:
   • Understand application logic: Ensure that the testing tools have a deep understanding of the application’s logic and behavior. This can be achieved by providing detailed documentation and context to the testing team.
   • Behavioral analysis: Use tools that can perform behavioral analysis to better understand the normal operation of the application and distinguish it from potential vulnerabilities.
3. Regular updates and maintenance:
   • Update signatures and databases: Keep the vulnerability databases and detection signatures of your testing tools up to date to ensure they are using the latest and most accurate information.
   • Patch management: Ensure that your web application is regularly patched and updated to reduce the likelihood of false positives related to outdated components.
4. Manual verification:
   • Double-check results: Manually verify the results of automated tests to confirm the validity of identified issues. This can help filter out false positives in pen testing.
   • Pen testing by human experts: Engage experienced pen testers who can manually test the application and provide more accurate and context-aware results.

The human advantage of PTaaS

Outpost24’s pen testing as-a-service (PTaaS) solution combines the benefits of automated vulnerability scanning with the depth and precision of manual penetration testing, securing the advantages of both technology and human expertise. With its context aware risk scoring capability, Outpost24’s PTaaS solution lets security teams to prioritize remediation efforts based on the vulnerabilities that pose the greatest dangers to their organization.

Its automated scanning capability balances speed and results through an application security scanner that enables your business to achieve continuous monitoring. This automated advantage helps to address a key drawback of traditional pen testing, which can take weeks to set up, leaving vulnerabilities exposed for longer, even while threat actors can weaponize a vulnerability in shorter time periods than ever before.  

Perhaps most importantly, it combines the benefits of automation with human knowledge, expertise and skill. This greatly reduces the risk of false positives in pen testing. Our experienced pen testers lead the process, delivering the most accurate view of vulnerabilities. This includes the business logic errors and back doors that automated scanners may have missed. 

Improve your pen testing process today

Every organization is different, and the risk of false positives can vary. By applying human experience and intelligence to your pen testing, you can make the most of automated tools, leveraging their speed and combining it with human intuition. This balanced approach is the key to finding the real weaknesses in your networks – and building your defenses. Speak to an Outpost24 expert about how PTaaS could fit in with your organization.