How does Dynamic Application Security Testing (DAST) work?
DAST solutions identify potential input fields within an application and then send various unusual or malicious inputs to them. This can include both attempted exploits of common types of vulnerabilities – such as SQL injection commands, cross-site scripting (XSS) vulnerabilities, and long input strings – and unusual inputs that might uncover issues with input validation and memory management within an application.
Based on the application’s response to various inputs, the DAST tool identifies whether or not it contains a particular vulnerability. For example, if an SQL injection attack provides unauthorized access to data or an application crashes due to invalid or malformed input, then this indicates an exploitable vulnerability.
Why DAST is important
DAST solutions are designed to identify potential vulnerabilities within an executing application. This makes it possible to find configuration or runtime vulnerabilities that may impact the application’s functionality and security.
Pros and Cons
DAST solutions are a vital component of an enterprise application security strategy. Some of the main advantages of a DAST solution include:
- Detecting Runtime Issues: DAST scanners interact with a running application, enabling it to detect both compile-time and runtime issues within an application.
- Low False Positive Rates: DAST identifies vulnerabilities by exploiting them, enabling it to verify that a potential vulnerability actually poses a threat to an application’s functionality or security.
- Language Agnostic: DAST solutions test running applications in a black-box assessment, meaning that it can be used for applications written in any language for any environment.
Despite its numerous advantages, DAST is not a comprehensive solution. Some of the main disadvantages of DAST include:
- Late Appearance in SDLC: DAST requires access to a running application, meaning that it can only be performed late in the Software Development Lifecycle (SDLC) when vulnerabilities are more expensive to remediate.
- Vulnerability Location: DAST solutions can identify that a vulnerability exists within an application but does not have access to the source code so it cannot find the exact location within the codebase.
- Code Coverage: DAST solutions evaluate a running application, meaning that they might miss vulnerabilities in parts of the code that are not executed.
DAST vs. SAST
Static Application Security Testing (SAST) performs analysis of an application’s source code rather than interacting with a running application. DAST and SAST are complementary approaches to application security. Some of the main differences between DAST and SAST include:
- Test Type: SAST is a white-box vulnerability scan with full access to the application’s source code, while DAST is a black-box assessment with no knowledge of the application’s internals.
- Required Code Maturity: SAST solutions scan source code, which enables them to run on partial code. DAST solutions can only analyze running applications, which requires more mature code.
- Phase of SDLC: SAST’s ability to analyze source code allows it to be performed earlier in the SDLC than DAST, which requires a running application.
- Remediation Cost: Since SAST analysis occurs earlier in the SDLC, it costs less to fix any identified vulnerabilities than with DAST. The later in the SDLC, the more code that might need to be fixed and the less time available to do so.
- Vulnerability Coverage: DAST solutions are able to identify runtime vulnerabilities and configuration errors that SAST solutions cannot since code is not running during SAST analysis.
- Location of Vulnerability: SAST solutions scan source code, so they know exactly where in an application a vulnerability is located. DAST only knows that a vulnerability exists but can’t point to a particular line of code.
- False Positive Detections: DAST interacts with an application, enabling it to determine if a potential vulnerability actually impacts an application’s functionality. SAST only works based on a model of an app and has a higher rate of false positives.
Improving Application Security with DAST
Strong application security practices are vital for protecting cloud-based workloads against exploitation. DAST provides the ability to detect a wide range of vulnerabilities, especially when combined with SAST. By identifying vulnerabilities before they can be exploited by an attacker, SAST and DAST dramatically decrease the cost of remediation and their potential impacts on an organization and its customers.
Check Point CloudGuard complements SAST and DAST vulnerability scanning with runtime application protection for cloud-based workloads. CloudGuard AppSec analyzes each request in context and learns as your organization’s applications evolve.
To learn more about Check Point CloudGuard AppSec and its ability to improve the security of your organization’s cloud-based applications and workloads, check out this ebook. Then, sign up for a free demo to see the capabilities of CloudGuard for yourself.
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