The Art and Science of Secure Coding: Key Practices that Stand Out

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Flaws in code lines, file system and data input methods make up the core security vulnerability of any application. This is what we address through secure coding practices. Secure coding guidelines stand out as the last battling army before the enemy line of security risks and threats. Basically, secure coding practices will make developers more capable of addressing security risks by following time-tested principles, make them more efficient through streamlined coding practices and make a qualitative impact on the application in more ways than one.

1. Addressing input validation vulnerabilities

At a time when there are an overwhelming number of web applications, the input from web users exposes every app to a whole range of security threats. But many developers who still just consider security as an add-on feature just fail to understand the proportion and potential of such threats. Only when the security is vandalized by someone publicly do they grope for additional measures leading to security patchworks. When user inputs make an application vulnerable to security threats, there can be an array of contributory reasons including lousy design, flaws in configuration, vulnerable coding and most importantly unverified user inputs. Among all others, unverified user input is one of the principal reasons that put your application at risk. This is addressed through secure input validation practices as mentioned below. Any patchwork after developing an app involves a considerable amount of cost and difficulties. The problem is that finding and fixing bugs after the app's initial development can be as expensive as building a new app. Meanwhile, concurrently testing, finding and fixing bugs in the process of development can lower this cost significantly and allow faster time to market for the product. The second most important aspect which is often not taken seriously is the little difference that external detection systems firewalls cause in the post-development detection process. They just cannot do anything with the malicious attacks during the software implementation or at the design stage. All these external systems can only play their role in the post-development period. So, mitigating the input validation procedures and all measures related to finding and fixing bugs during the development process is what should be aimed at to address security issues. The widely recommended approaches are provided below.

• Addressing security vulnerabilities during development only.
• Taking stock of the detailed vulnerability classification as presented by different organizations on the basis of impact, prevalence, detectability, exploitation, etc.
• Input validation vulnerabilities like XSS and SQL injection, which remain some of the most prominent threats to web application security, need to be addressed with priority.
• These vulnerabilities need to be continuously addressed throughout different phases starting with the planning and requirement analysis to the testing and deployment phases.

2. Addressing security risks emerging from compilers and frameworks

Compiler poses a high-security threat to any application. Frameworks are also showing that apparently safe behavior can end up causing security issues. Let us understand the problem in detail. Though some frameworks come as capable of protecting the front end from XSS and CSRF attacks and the back end from SQL injection attacks, you need to constantly incorporate the security logic at appropriate places on the basis of use cases of the application. This exposes you to security vulnerabilities in the implementation, as the framework depends exclusively on developers for incorporating as per the use cases. A compiler, on the other hand, remains completely in darkness on where user input is involved in the function of an app. By pushing checks for buffer overruns in many places, it can drastically slow down the performance. But after directing it about the context, the compiler can put forth an additional security layer on its own. Now let us mention here some tried and true rules of using compilers to enhance security.

• Use the compiler errors positively instead of ignoring all of them as irrelevant.
• Compiler warnings often indicate information about future bugs.
• Often developers remain in darkness about the branch of a code containing an “if” statement that doesn't comply with the value. This is when you need to take compiler warning seriously and check the code lines.
• Some issues and bugs are even not found during testing, and compiler warnings can alert you about them during development. Compiler warnings can notify of some common problems like uninitialized variables or forgetting to return function value. These issues may remain undetected even after testing the app, with compiler warnings offering scope to address them.
• Finally, always consider using static and dynamic analysis tools to detect and address compiler issues.
• Static analysers without running the code can identify issues like buffer overflows, null references, etc. Static analysers can also work great in performance and security analysis.
• While static analysers can only detect issues without running them, many problems still escape their ambit. Dynamic analysers examine what is going on when the application is working and so can detect many issues that static ones cannot.

3. Using effective quality assurance techniques

Finally, the role of good quality assurance always stands out in detecting and eradicating security vulnerabilities. An effective quality assurance process should incorporate all latest testing protocols like fuzz testing, penetration testing and source code audits. Apart from these, there should also be independent reviews of security to evaluate the shortcomings from an independent perspective. Fuzz testing: Fuzz testing as a very simple and effective technique can easily detect all significant issues. Before your software comes into deliverable condition, it can spot the real-world failures and notify about the potential risks of attacks that can be addressed. This is how fuzz testing works.

• You need to prepare a file in a correct format for input. Some part of the file should have randomly fetched data.
• Now by opening the file with the program, you need to evaluate the result.
• You can use random data and take advantage of ways to detect what and when the program fails to work with or respond.
• You can do initial fuzz testing manually and then go for automation to see the effect in large scale.
• The key is to detect what and how the application defines when the input data is corrupt. By randomly feeding data, you need to recognize the file responsible for not triggering error alerts, dialogue, message, etc.

Penetration testing: A penetration test is nothing but an evaluation of the response of an application against a simulated cyber-attack on the computer. In the case of a web application, this test is used to enhance the web application firewall (WAF). Here's how penetration testing works.

• Defining the scope and objective of a test, keeping both the systems and testing methods in consideration.
• Assessing how the target responds and all the potential vulnerabilities.
• Evaluating responses to several types of intrusion attempts through static and dynamic analysis.
• Using different types of web application attacks like SQL injection, cross-site scripting and others.
• Evaluating how these vulnerabilities can turn into persistent threats affecting the systems targeted.
• Surmising the results of the test through a report comprising particular vulnerabilities, the data accessed and exposed and the time required to detect the attack.
• Analyzing the report to fix all the identified vulnerabilities by the security experts.

Source Code Audit: Source code audit is used to detect security vulnerabilities that arise when native code is compiled for building an application. It is mainly about detecting in-depth flaws that remain unnoticed when transforming the source code to machine code for being executed by the machine. Source code audit can easily detect vulnerabilities that are part and parcel of any application using third-party software libraries. Often these libraries come with complicated protocols and file formats, and many of them are seen to have a number of security flaws that make other applications vulnerable when they are used. A source code audit helps applications to address such flaws and vulnerabilities from third-party libraries.

4. Addressing security vulnerabilities for DevOps platform

The DevOps as a platform has transformed the software development lifecycle with many value additions. Apart from ensuring agility and robust collaboration on diverse tasks, DevOps enhances the consistency through refined processes devoid of human errors. That's pretty impressive. But sometimes when keeping the pace and agility, DevOps also makes software development vulnerable to specific security threats. Let us briefly look into the ways these security vulnerabilities can be addressed on the DevOps platform.

• Rely on a DevSecOps model with integrated security considerations in the workflow. DevSecOps is a well-equipped model with integrated cybersecurity and administrative functions ranging from identity and access management (IAM), firewall management, code evaluation and vulnerability assessment in the workflow and privilege management.
• Ensure a transparent policy for cybersecurity and governance. This will help in preventing coding with security vulnerabilities.
• Make sure that DevOps security tools and processes are automated. By enforcing automated processes and tools, human errors can be minimized and security can be strengthened to a great extent.
• Ensure thorough evaluation and assessment of all permitted and non-permitted tools, user accounts and devices from time to time. This will minimize security vulnerabilities and threats intruding from outside.
• Conduct frequent vulnerability testing to track weaklings in code and embedded errors that can be improved or addressed adequately.
• Conduct scanning to track the misconfigurations and errors that remained unnoticed. A configuration test will help to address incoherence or performance issues as well.
• Create a separate password management protocol like DevOps secrets management.
• Lastly, to ensure non-violation of access rules and to prevent unsolicited accesses, keep the privilege access rights to a minimum and use it very sparingly. By enforcing least privilege access protocol, you have to restrict access for developers and testing professionals onto certain processes.

Conclusion

The science of secure coding cannot be achieved without the meticulous consideration of every type of vulnerability and threat. On the other hand, the art of secure coding involves how inconspicuously you can embed and embrace security tools, protocols and best practices throughout the software development lifecycle.

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Author Bio: Juned Ghanchi is a CEO and proud co-founder of Indian App Developers, a place to hire experience team of app developers India for Android and iPhone application development. He frequently contributes too many of the web's prominent technology sites & blogs about mobile technologies, mobile app etc. Editor’s Note: The opinions expressed in this guest author article are solely those of the contributor, and do not necessarily reflect those of Tripwire, Inc.