What is Dynamic Application Security Testing (DAST)

Say an e-commerce platform rolls out a user-friendly search box allowing customers to easily search for products on the app, but the development team didn’t implement strict search input handling procedures. As a result, all inputs are directly inserted into the database queries without validation, allowing cyberattackers to manipulate the queries to perform SQL injection (SQLi) attacks. The database would then execute malicious SQL code, which could give an attacker access to sensitive customer information, including names and credit card details, which could represent large financial and reputational loss for the firm.

The above scenario is hypothetical, yet SQLi attacks are very much a real-world risk for modern applications. Fortunately, it is possible to prevent these and other dangerous cyberattacks. The key is to test the live application from a cyberattacker’s perspective.

This approach of probing a live application from the outside in is known as Dynamic Application Security Testing (DAST), and it enables development teams to discover and fix security weaknesses before a real attacker can take advantage of them.

What is Dynamic Application Security Testing?

DAST is the process of testing a running application by simulating real-world attacks against it. Automated DAST tools interact with the app at runtime – in the same way that outsiders like malicious hackers would. By assessing the running app from a real attacker’s perspective, DAST can uncover many security vulnerabilities that only appear in real-world use, such as:

• Authentication issues
• Server configuration errors
• Input validation errors
• SQL injections
• Cross-site scripting (XSS) issues
• Security logging and monitoring failures

Key Benefits of DAST

DAST is an invaluable security testing approach because it offers all these benefits:

Early vulnerability detection

Dev teams can implement automated and repeatable DAST on apps in staging or production. This enables them to detect exploitable, real-world vulnerabilities and apply early fixes, thus preventing potentially catastrophic cyberattacks and data breaches.

Minimal need for manual intervention

Automated DAST tools can identify and prioritize runtime vulnerabilities in real time. Little to no manual input is needed to test the app and uncover its flaws.

Higher development productivity

With automated tools, developers can run scans on every build and get immediate feedback. This facilitates fast issue remediation and enhances development productivity and efficiency.

Limitations of DAST

DAST is an effective way to test running applications and proactively discover their real-world vulnerabilities. However, the approach also has some limitations:

• It may miss logic flaws, deeper code-level flaws, complex authentication issues, or hidden code paths, reducing security coverage.
• Tests can be time-consuming – especially for large or complex apps – delaying app deployment.
• It detects vulnerabilities, but typically doesn’t clarify its exact location within the code.
• It may flag harmless behaviors as risky (false positives), resulting in wasted time and resources, and distracting security teams from genuine threats.
• Tools must be properly configured to understand the application’s context and simulate attacks accordingly.

The Role of DAST in Building a Comprehensive Security Strategy

DAST is a highly effective testing methodology that can maximize security coverage and substantially strengthen application security, particularly when it is combined with other methodologies.

DAST and SAST

Static application security testing (SAST) is a white-box testing approach that looks at applications from the inside out. It is useful for identifying vulnerabilities in code prior to app deployment, such as:

• Coding errors
• Insecure functions
• Logic flaws
• Outdated libraries
• Hard-coded credentials

However, many flaws become apparent only when the app is fully functional and live. SAST cannot detect these issues.

For example, real-world attackers attempt to modify app functionality or steal critical data by manipulating database queries (SQLi) or injecting malicious scripts into web pages (XSS). They also take advantage of misconfiguration errors and frequently exploit unprotected or improperly secured API calls for malicious purposes. To defend against these runtime, external-facing attacks, it’s essential to simulate real attacks on the app and observe its response as it is running. For this, DAST is essential.

That said, no one approach is “better” than the other. SAST and DAST are complementary approaches that address different kinds of security issues. For example, SAST is useful to analyze static environments and detect code-level weaknesses, while DAST is ideal for discovering runtime vulnerabilities that increase the risk of real-world cyberattacks. By using these approaches together, development teams can address the coding flaws that DAST cannot identify and the exploitable vulnerabilities that SAST usually misses. This is why, to minimize the app’s security risk, it’s best to perform DAST and SAST together.

DAST and Pentesting

Like DAST, penetration testing (pentesting) is done on a running system. But unlike DAST, pentesting is not fully automated. Automated DAST tools follow predefined patterns and lack contextual awareness, and so cannot perform deep explorations or discover complex flaws. In contrast, skilled pentesters manually test systems in-depth to discover and highlight exploitable weaknesses, realistic exploit paths, and chained attacks.

However, DAST has one significant benefit over pentesting: it uses automated tools and is therefore repeatable and scalable. It’s also less time-consuming and cheaper than human-dependent pentesting.

As with DAST and SAST, DAST and pentesting are not alternative approaches, but complementary ones. Manual pentesting is great for in-depth, creative, and contextual testing from an attacker’s perspective, while DAST is best suited for automating attack simulations on apps in staging or production. Where automated DAST tools can discover common, known vulnerabilities like SQLi, XSS, and misconfigurations, human-delivered pentesting is great for discovering complex attack paths. This is why it’s advisable to combine DAST and pentesting.

Strengthen Your Application Security Program with BreachLock

BreachLock offers DAST, SAST, and API Fuzzing capabilities alongside human-driven and continuous penetration testing services tailored to enterprises’ unique security needs.

BreachLock DAST uses a Black Box approach to simulate external attacks throughout the SDLC, helping proactively identify vulnerabilities that could surface later in production. By addressing risks early, enterprises can mitigate threats before they’re exploited and strengthen overall application security.

With Penetration Testing as a Service (PTaaS), BreachLock’s hybrid delivery model combines human expertise, AI efficiency, and automated scalability, giving security teams the flexibility to choose methodologies aligned with their AppSec goals.

Taking it a step further, BreachLock also offers Adversarial Exposure Validation (AEV), a Gen AI-powered autonomous red teaming tool that allows enterprises to launch real-world attacks on their applications and other assets to test where their defenses pass and fail. This allows users to not only identify vulnerabilities, but also better understand which of them open viable, high-impact attack paths for adversaries.

Ready to strengthen your application security posture? Schedule a free discovery call to see how BreachLock’s DAST and PTaaS solutions can help.

About BreachLock

BreachLock is a global leader in offensive security, delivering scalable and continuous security testing. Trusted by global enterprises, BreachLock provides human-led and AI-powered Attack Surface Management, Penetration Testing as a Service (PTaaS), Red Teaming, and Adversarial Exposure Validation (AEV) solutions that help security teams stay ahead of adversaries.

With a mission to make proactive security the new standard, BreachLock is shaping the future of cybersecurity through automation, data-driven intelligence, and expert-driven execution.

Know Your Risk. Contact BreachLock today!

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BreachLock Labs