Software Development Life Cycle: SAST and SCA Combined

Let’s dive into how tiny details in software development can lead to big security issues, and how using SAST and SCA together can strengthen your code’s security. We’ll see why blending these tools within the Software Development Life Cycle (SDLC) is great for making safer software.

Author: Elif Tutar — AppSec Researcher aka JigglyPuff ✨

As practitioners in the field of secure software development, we are often equipped with tools like SAST and SCA. Imagine the compounded benefits if we could merge these tools’ functionalities into one seamless product.

In this discussion, we will break down the distinct roles of Software Composition Analysis and Static Application Security Testing.

SCA — Software Composition Analysis

SCA is about keeping your software safe by keeping an eye on the external bits of code you use, like open-source components, and their licenses. It checks your software to find and manage these parts, making sure they’re safe and legal to use.

Big security incidents like SolarWinds show why SCA is so important. Hackers often hit the weakest part, like old or hidden code that gets into your software without you realizing it. SCA helps avoid this by using wide-ranging sources for security checks, not just the standard databases. It’s become a key tool for fighting cyber threats, especially with so much open-source code in use today.

It’s very dangerous to open a package without knowing what’s inside, especially if you don’t know where it came from

Open Source License Compliance: SCA tools facilitate compliance with open-source licenses by reporting a detailed list of licenses associated with dependencies. Strong policy engines within SCA tools can also be configured to block builds if an out-of-policy license is detected.

SBOM Generation: SCA tools play a crucial role in generating Software Bill of Materials (SBOMs), providing a detailed inventory of software components.

dependency graph example from codethreat platform

Open Source Vulnerability Management: Beyond creating an inventory of known vulnerabilities (CVEs), SCA aids in prioritization and remediation. For instance, tools like NIST National Vulnerability Database provide CVSS and EPSS scores for vulnerabilities to assist in prioritization. Moreover, they offer insights into the fix and code path, streamlining the remediation process.

example sca output

In summary, Software Composition Analysis is an integral part of the software development process, enhancing security by ensuring comprehensive identification, tracking, and management of opensource components and potential vulnerabilities

SAST — Static Application Security Testing

Static Application Security Testing is an important technique used to check the building blocks of an application — like its source code or the ready-to-run code — for any weak spots that could be a security risk. This check is done without running the application. It’s usually done early on when the application is being created, so that developers and security experts can fix these issues before the application is finished and used by others.

SAST operates by identifying potential vulnerabilities through predefined rulesets or security patterns rooted in established security best practices. These rulesets are crafted based on common coding errors and known security pitfalls, including issues such as SQL injection, cross-site scripting (XSS), buffer overflows, and other vulnerabilities that could potentially enable threat actors to escalate privileges, access restricted data, or execute malicious code.

SAST Techniques

Data Flow Analysis: This method tracks how data traverses through the application. It encompasses control flow analysis to understand the execution order of different code sections and code path analysis to comprehend conditional statements, loops, and varied execution paths.

Taint Analysis: Focused on tracing the flow of untrusted or tainted data, this technique helps identify potential security risks arising from improperly sanitized or validated user input.

points-to (pointer) analysis decision making

SAST Capabilities:
• Pinpoint Flaws in Proprietary Code
• Detect Weaknesses Early in the SDLC, Reducing Costs
• Identify Weaknesses Before Code Deployment into Production

A SAST tool is the embodiment of this methodology, focusing on addressing security issues within an organization’s proprietary software. By scanning the source code for known vulnerable code patterns, SAST tools generate insights into potential security flaws and vulnerabilities. Operating early in the SDLC, these tools provide real-time feedback to developers during coding, facilitating issue remediation before code progression to subsequent phases of the SDLC.

SDLC process is integral to SCA and SAST. What does SDLC stand for?

The Software Development Life Cycle (SDLC) encompasses the systematic process of planning, designing, implementing, testing, deploying, and maintaining a software project. This process ensures the organized management of software from its inception to completion

a brief code repository security operations

The Role of SCA and SAST in SDLC:

Software Composition Analysis and Static Application Security Testing play vital roles in the software development lifecycle.

SCA follows the “shift-left” principle, becoming an integral part of the early development stages. Here, it offers ongoing feedback to developers, informing them about the security and licensing status of open-source components. This early integration allows for the timely identification of potential risks and provides developers with opportunities to address issues promptly. With the “shift-everywhere” approach, SCA’s influence extends beyond development, reaching testing, integration, and operational stages. Throughout the software life cycle, SCA remains vigilant, continuously monitoring and managing the security status of open-source components.

Similarly, SAST is heavily employed in the initial phases of development, focusing on code writing and compilation. During these stages, SAST identifies possible security vulnerabilities, offering developers immediate insights for intervention. Adopting the “shift-everywhere” perspective, SAST goes beyond development, actively participating in testing, integration, and operational stages. Its goal is to provide ongoing monitoring and resolution of security vulnerabilities throughout the entire lifespan of the application.

Shift-Everywhere Approach:

In both cases, the “shift-everywhere” approach expands the effectiveness of SCA and SAST beyond the early stages of development, integrating them into testing, integration, and operational stages. This approach promotes the widespread adoption of security considerations throughout every stage of the software life cycle, fostering the development of more secure software practices.

Comprehensive Security Analysis:

• SCA identifies security vulnerabilities in third-party components.
• SAST reveals security vulnerabilities in the source code through code analysis.
• When used together, they enable a comprehensive analysis of both external dependencies and the security aspects of original code.

Advanced Threat Detection:

• SCA identifies security threats in known third-party components.
• SAST detects unknown vulnerabilities at the source code level.
• When employed together, they provide a broader scope against both known and unknown security threats.

Remediation and Implementation Speed:

• SCA facilitates the rapid updating of libraries with identified security vulnerabilities.
• SAST, pinpointing errors at the source code level, provides developers with early warnings.
• When used together, these two methods enable the early detection and correction of errors, resulting in a faster and more effective security response.

Conclusion

while using AppSec tools like SCA and SAST is crucial for robust software security, it’s true that they can be challenging to maintain in real-life scenarios. The key is to integrate these tools in a way that aligns with and simplifies your organization’s existing practices, ensuring both effectiveness and ease of implementation. Balancing security needs with practicality is essential in today’s dynamic tech environment.