What are the common security code review pitfalls and how to avoid them?

Automated tools are invaluable for detecting common vulnerabilities, but relying solely on them can leave serious gaps in your security review process. In one project, we noticed that the automated scan failed to detect a logical flaw related to role-based access control. Manual review allowed us to identify this critical issue, which could have led to unauthorized access if exploited. The lesson here is that while automated tools are essential, combining them with manual code reviews ensures better coverage, particularly for issues tied to business logic and application flow.

?? agree with this strategy. I’d say to employ routine red teaming as well with research based or crowd sourced reviews if your code is in the open. BB programs can be helpful as well.

One of the best way to communicate the impact of the vulnerabilities to developes is by debeloping a small POC. This POC will have a short code exploiting the vulnerability present in the code. By communicating the language that developres understand , it also motivates them to fix the issues as developers take pride in their craft. The most common and critical vulnerabilities like Insecure Deserialization , Remote Code Execution , Prototype Pollution will be best described by going deep into code. We can also take help from Public Exploits available in Open Source Databases like ExploitDB or any Public Exploits on Github

Following up after code remediation is crucial, yet it's often neglected. I worked on a review where several medium-severity vulnerabilities were flagged and addressed by the development team. However, upon further inspection during the follow-up, one of the fixes introduced a new vulnerability by inadvertently weakening a critical encryption function. This experience highlights the importance of performing a second round of reviews to ensure that fixes are properly implemented and no new issues have been introduced in the process.

Code reviews are a learning opportunity for the entire team, not just a gatekeeper task. When developers don't actively engage in reviews or understand the rationale behind identified issues, they are likely to repeat mistakes. Encourage knowledge sharing by discussing common patterns, offering training, and involving junior engineers in the process.

An often-overlooked aspect of security code reviews is educating developers as part of the process. While conducting reviews for a startup, we held short training sessions after every review to explain the security flaws and best practices. This not only helped reduce the number of issues in subsequent code submissions but also fostered a culture of security-minded development. Encouraging a learning environment can significantly enhance the effectiveness of security reviews in the long run.

Security code reviews should not exist in isolation; they must be part of a broader secure development lifecycle (SDLC). Ensure that all team members are trained on secure coding practices, integrate security tools into the CI/CD pipeline, and regularly update your review processes to reflect the evolving threat landscape. Continuous improvement is key to keeping your codebase secure.

Automate repetitive tasks like code formatting, static analysis, dependency scanning, and testing using tools integrated into CI/CD pipelines. This enhances consistency, efficiency, and early detection of issues, enabling reviewers to focus on complex security concerns, ultimately improving overall code quality and security posture.