What is Static Application Security Testing (SAST)?

Static Application Security Testing (SAST) is a vital technique used in the field of software development and cybersecurity to detect and prevent potential security vulnerabilities in applications. It is an automated process that analyzes the source code or binary of an application without executing it. By examining the code itself, SAST tools identify coding flaws and weaknesses that could be exploited by attackers.

The primary objective of SAST is to identify security issues early in the development life cycle, when they are less expensive and time-consuming to fix. By detecting vulnerabilities at the source code level, SAST helps developers address security concerns before the application is deployed or released to end-users.

SAST employs a variety of techniques to perform its analysis. These techniques include lexical analysis, data flow analysis, control flow analysis, and pattern matching. During lexical analysis, the tool breaks down the source code into its basic elements, such as keywords, variables, and operators. Data flow analysis examines how data is passed through the application and checks for any potential security risks, such as unvalidated inputs or insecure data storage. Control flow analysis studies the flow of execution within the application to detect any anomalies or suspicious behaviors. Pattern matching involves searching for known patterns of vulnerabilities, such as SQL injection or cross-site scripting (XSS).

The SAST process typically involves the following steps:

1. Code analysis: The SAST tool scans the source code, analyzing each line and identifying potential security weaknesses or vulnerabilities.
2. Vulnerability detection: The tool compares the code against a database of known security vulnerabilities, searching for matches or patterns that indicate potential risks.
3. False positive reduction: SAST tools may generate false positives, highlighting code sections as vulnerable even though they may not pose an actual security risk. False positives need to be manually reviewed and eliminated.
4. Reporting: SAST generates a comprehensive report detailing the identified vulnerabilities, along with information about their severity and location in the code. This report helps developers understand and prioritize the issues to address.

SAST offers several advantages in ensuring application security. First and foremost, it provides an early identification of vulnerabilities, enabling developers to fix them during the development process rather than in production. This reduces the likelihood of security breaches and associated costs. Additionally, SAST tools can be integrated into the software development lifecycle, providing continuous security assessments throughout the development and testing stages.

However, SAST also has its limitations. It relies on the accuracy and completeness of the source code provided, meaning that any code not analyzed will not be included in the security assessment. SAST tools may also generate false negatives, missing certain vulnerabilities due to complex or evolving attack techniques. Furthermore, SAST may not be effective in detecting runtime vulnerabilities or vulnerabilities caused by misconfigurations in the deployment environment.

In conclusion, Static Application Security Testing (SAST) is an essential security practice that helps identify potential vulnerabilities in applications by analyzing the source code or binary. By integrating SAST into the software development lifecycle, developers can proactively address security concerns and minimize the risk of exploitation. Although SAST has its limitations, it remains a valuable tool in the overall security strategy, complementing other security measures such as dynamic testing and manual code reviews.

Code Insights from BlueOptima

Code Insights can help your developers identify vulnerabilities in open-source libraries at a commit level before these go into the CI/CD pipeline. Accordingly, your developers are able to fix and mitigate risk earlier and reduce the cost of redeployment. Learn more about Code Insights and how we can help optimise your software development processes.