Secure Coding: What You Need to Know
With software being central to today’s interconnected world, making it secure has become more crucial than ever. Fortunately, decreasing cyber risks and achieving more secure applications is well within the reach for any company developing software out there – they should simply write the code with security in mind.
What is secure coding and why is it important?
To grasp the concept of secure coding, let’s first explore what source code is all about. Source code consists of instructions that determine how an application should work, behave and operate. It serves as the foundational blueprint, detailing operational procedures and responses to various inputs. Initially written in a human-readable form – that we call programming language –, the source code is translated into machine-readable instructions, the binary code that computers understand and execute.
Secure coding is about writing the source code in a way to protect applications from vulnerabilities and potential threats. This includes using specific coding techniques and adhering to coding best practices to mitigate security risks, safeguard against data breaches, prevent unauthorized access, or make malicious code execution hard. This includes both writing the source code securely and maintaining any third-party libraries in a secure state.
Simply put, the goal is to have an application that does well what it should do, but that doesn’t do anything that it shouldn’t.
By prioritizing secure coding principles, developers aim to create applications that are resilient and robust against malicious attacks. This proactive approach ensures optimal performance without compromising sensitive data or exposing vulnerabilities. Indeed, these weaknesses can lead to substantial reputational risks and financial losses, sometimes reaching millions, as evidenced in notable cases like Heartbleed, Log4Shell, or the Microsoft Exchange breach. Security incidents often originate within an application’s software and codebase, underscoring the critical need for robust secure coding practices to establish a solid foundation for software security.
Key Secure Coding Practices
To effectively adopt secure programming, developers should adhere to coding best practices. Here are some key basic practices that should be implemented.
Data security – access control, rigorous encryption, and effective secrets management
Implement robust authentication and authorization mechanisms alongside standard encryption algorithms to protect data in transit and at rest. Don’t hardcode sensitive information such as passwords or access keys directly into your code or the code repository, even if you use available tools for secrets management in your applications.
Input validation
Obviously, you cannot prepare your code to work well for all possible inputs. At the same time, inputs are the ultimate channels through which the attackers will feed in something unexpected that your code is not prepared for. And that’s exactly where input validation comes into picture: just reject anything your code may misbehave for and accept only those values you are sure your code is OK with. And remember, the default behavior is to reject; so always apply allowlists for input validation, do not use denylists.
Avoid using components with known vulnerabilities
Third party components and libraries – regardless of being commercial tools or open-source – can save time but are also common entry points for vulnerabilities. If you have a vulnerability in these, it is not your fault, but is still your problem! Avoid using components with known vulnerabilities, which means keeping your dependencies up to date all the time and continuous monitoring of sources of information for new vulnerabilities literally popping up on a daily basis.
Automated scanning and code reviews
Combining regular secure code reviews and automated scanning tools can prevent many types of attacks, like Cross-site scripting (XSS) and SQL injection, just to name a few (XSS runs malicious code under your domain, while SQL injection steals or manipulates your internal data). Detecting the usage of vulnerable components is also a step you can easily automate these days. There are of course some types of vulnerabilities these tools cannot find; but the burden of the problems are of nature they can find and pin-point for you!
Shift left approach
Integrating secure coding practices across the Software Development Life Cycle (SDLC) is crucial to effectively address vulnerabilities. By embracing a “shift left” approach, some of the security-relevant activities are moved from later stages to the beginning of the SDLC. This ensures that security measures are implemented from initial requirements gathering and coding through testing, deployment, and ongoing maintenance. Remember: the earlier you realize a problem, the cheaper it is to fix it!
Secure coding training
Most importantly, securing your applications should start with fostering a robust security culture within the organization. This involves educating developers, IT teams, management, and all stakeholders on best practices and proactive threat management. Many SDLC schemes, like Microsoft’s Security Development Lifecycle (SDL) or SAMM also recognize this. Bottom line is: train your developers to fix the (in)security of your application at its core – the developers mindset!
Secure Coding FAQ
What constitutes a security testing?
Security testing involves identifying and fixing potential vulnerabilities in your code before they get to production. It’s not about how the system should work – that’s functional testing. It’s about how the system should NOT work. Security testing can be done manually, using automated tools, but the best approach is to blend the two approaches.
Why is a secure development framework important?
A secure development framework ensures that code is developed, tested, and deployed in a way that minimizes the risk of introducing vulnerabilities. It includes secure infrastructure, tools, and practices that collectively enhance the overall security of the whole software development lifecycle.
What does OWASP secure coding entail?
OWASP secure coding refers to a collection of best practices, guidelines and cheat-sheets provided by the Open Worldwide Application Security Project. These sources outline general software security principles and specific coding requirements to help developers write secure code. OWASP is not just the Top Ten after all!
Are there any standards or guidelines in this domain?
Yes, there are many. Some guidelines are created for specific programming languages, like SEI CERT C, C++ or Java secure coding guidelines. Yet some others are created for specific lines of business, like MISRA for automotive and transportation, or PCI DSS for banking and financial services. And, there are some databases of vulnerabilities from which one can also learn a lot, like the Common Weakness Enumeration (CWE) or the Fortify Taxonomy.
How does secure coding impact business?
Secure coding protects businesses from financial losses, reputational damages, and legal consequences by preventing data breaches and other security incidents. It helps maintain customer trust and at the same time ensures compliance with regulatory requirements.
In conclusion, incorporating secure coding practices is essential for any organization developing applications in order to mitigate risks and protect software from cyber threats. By implementing these key practices, developers establish a robust foundation to ensure the integrity of applications throughout their lifecycle.
Cydrill’s award-winning training program offers a blended learning journey for software engineers to ensure they are well-prepared for secure coding. With its gamified environment and content, Cydrill empowers developers to take the lead in securing our digital future.