Source Code Security Best Practices: A Complete Guide

Software supply chain attacks are on the rise and show no signs of slowing. According to a late 2022 study, supply chain attacks increased 633% compared to the previous year, with over 88,000 documented cases. 

Even more alarming – this follows a 650% raise in 2021 and a 430% increase in 2020. If the trend continues upward, source code security will become one of the biggest issues for software developers. 

Now, attacks against major companies and government agencies typically grab the biggest headlines. For example, in 2023 a Lapsus$ teen hacker made the news for leaking footage of Grand Theft Auto VI. In 2024, it was Game Freak’s turn. Over 2.600 employee personal data was exposed, along with several Pokémon documents, source code, and concept art.

This can give smaller companies a false sense of security, as if only bigger organizations are under threat. However, numbers tell a different story. 

About 43% of cyberattacks target small businesses. This means source code security must be a top priority for every software company, from global enterprises to small startups, and everyone in the supply chain. 

For companies working with remote developers, the risks multiply. Remote devices can be entry points for malicious actors and expose your IP, sensitive data, and assets. Remote development reinforces the need for strong access controls, endpoint protection, and continuous monitoring.

With all of this in mind, let’s look into some source code protection best practices.

What are the risks of source code security breaches? 

Let’s start from the beginning. Your source code is the foundation of your software. Its security directly impacts your product’s success, reputation, and competitive edge. Source code leaks threaten your intellectual property, expose sensitive data, damage your public reputation, and destroy customer trust. 

Let’s take a deeper look at all the risks and what they truly mean:

• Intellectual property theft: unauthorized access to your source code allows unscrupulous individuals or organizations to replicate or modify your product without permission. 
• Data breaches: source code security breaches expose sensitive information, such as proprietary algorithms, access credentials, and employee or customer data.  
• Competitive disadvantage: leaked source code reveals your product’s functionalities, architecture, upcoming releases, and trade secrets to competitors. 
• Reputation damage: security breaches severely damage your company’s reputation and erode customer trust. 
• Legal ramifications: a breach of source code security can result in legal battles to protect your intellectual property rights. 

What are the key source code security best practices?

Securing your source code is paramount to ensuring the integrity and security of your software. But what can you do to make sure your source code remains secure? From automated code scanning to privilege access control, 2FA and encryption tools, there are plenty of effective measures you can take? Let’s look at some of the best practices to ensure source code security:  

Use Automated Code Scanning

Automated code scanning tools are a developer’s best friend to identify vulnerabilities and security weaknesses early in the development process. Some popular code-scanning tools include:  

• Kiuwan™: this end-to-end application security platform has a comprehensive toolset that includes SAST, SCA, and QA. Kiuwan™ integrates with Assembla, so you can enable weekly code scans for free. Kiuwan will then flag vulnerabilities and threats inline with your code commits in Assembla.  
• SonarQube: SonarQube is an open-source code security platform that continuously inspects your codebase. It ensures your source code protection meets security standards and coding guidelines.
• Checkmarx: Checkmarx offers static application security testing (SAST) solutions that identify and fix security vulnerabilities during development.
• Semgrep SAST: Semgrep is an open-source static analysis tool that supports multiple programming languages and allows for custom rule definitions.

Limit user access

Limiting user access to your source code is crucial to prevent unauthorized changes and leaks. Implementing role-based access controls will ensure that only authorized people can access specific parts of the codebase. 

Version control systems like Perforce and SVN offer robust access control features, allowing administrators to define and manage user permissions effectively. If you’re using Git, you’ll need to deploy external tools or use a source code management platform, like Assembla or GitHub, with built-in security features. We’ll look into access controls in SVN hosting, Perforce hosting and Git below.

When working with remote developers, ensure that access permissions are restricted to only what is necessary for their role. Granular access controls can prevent overexposure of your repositories or accidental leaks.

Use two-factor authentication

Two-factor authentication (2FA) adds additional security to your source code repositories. With 2FA, users must provide two forms of identification, such as a password or a PIN, plus a one-time code sent to their mobile device or biometrics to access the codebase. This extra layer of security guarantees only allowed personnel can access the codebase and sensitive information, which contributes to a more secure software development ecosystem. 

If that’s not enough, some companies are also requiring multi-factor authentication (MFA), which means users need to use two or more factors to verify their identity. While this further increases security, it can be cumbersome for end-users. An alternative is using SSO with MFA, which simplifies user experience. However, if the SSO credentials are compromised, all connected accounts may be at risk.

For remote developers, 2FA becomes even more critical. Combine 2FA with location-based restrictions for added protection.

Create clear source code protection best practices & policies

Establishing clear and comprehensive source code protection for every developer and subcontractor is essential. These policies should cover code review processes, how to handle vulnerabilities, and guidelines for integrating third-party libraries. Having well-defined security policies improves consistency across the development team and reduces the risk of security breaches.

Remote developers should receive specific training on source code protection, including best practices for securing their endpoints, avoiding public Wi-Fi for access, and regularly updating their systems.

Verify copyright

Ensure that your source code’s copyright is verified and documented properly. Clearly indicate the ownership and licensing terms to protect your intellectual property rights. Using version control systems like Git, SVN or Perforce enables you to track code contributions and maintain a comprehensive history of copyright ownership.

Deploy encryption tools

Implementing encryption tools is another practice we recommend to ensure source code security. Use encryption techniques or tools like HashiCorp Vault and Azure Key Volt to safeguard sensitive configurations, passwords, or API keys stored within the codebase. 

When remote teams access source code via cloud-hosted repositories, ensure data in transit is encrypted with SSL/TLS and stored with robust AES 256-bit encryption. Implement strict logging and monitoring of remote access attempts to identify potential threats early.

What to do after a source code security breach?

Discovering a source code security breach can be a nerve-wracking experience for any organization. However, there’s no time to panic – you need to act fast. Reacting promptly and effectively is crucial to minimizing potential damage and protecting your assets. Here are the necessary steps to take when you discover or suspect a breach:

Contain the breach

As soon as you suspect a breach, contain the breach immediately. Try to isolate the affected systems and restrict access to the compromised source code. Start by disconnecting compromised systems from the network. Then block repository access for suspicious users. These first steps prevent further unauthorized access and limits the potential spread of the breach.

Investigate the scope

To determine the extent of the breach, conduct a thorough investigation. Review access logs or check audit trails to identify the specific code repositories or files that have been compromised, as well as any potential data or intellectual property at risk.

Notify relevant parties

Inform all relevant stakeholders about the breach. This includes your development team, management, and security personnel. Collaboration and communication are crucial during this phase. Don’t forget some regulations, like the EU GDPR, make it your duty to report personal data breaches to authorities.

Implement patches and fixes

If the breach exploited known vulnerabilities, apply patches and updates to fix the vulnerabilities promptly. Implementing security fixes is the first step to make sure those same vulnerabilities cannot be exploited again.

Review access controls

Evaluate and strengthen access controls and permissions to prevent similar incidents in the future. Limit access to critical source code repositories and enforce two-factor authentication for added security.

Improve monitoring and detection

What can be done to prevent this from happening again? Look for ways to enhance your monitoring and detection capabilities, so as to identify potential breaches early on. Automated code scanning, intrusion detection systems, and security event monitoring can aid in detecting suspicious activities.

Review incident response plan

After the breach, do a post-mortem to assess the effectiveness of your incident response plan. Identify areas for improvement and update the plan accordingly to enhance your organization’s security posture.

Source Code Security with Assembla

As a source code hosting provider for Git, SVN and Perforce, we understand that protecting source code is essential to secure your digital assets.

In more than 18 years in operation, no one has ever compromised Assembla’s cloud infrastructure. We’ve implemented several security measures, including:

• Permission controls: Assembla allows you to define advanced user access controls, so that only authorized personnel can access specific repositories and files.
• Data encryption: all data is stored on Assembla with AES 256-bit encryption. We also use SSL for data both in transit and at rest, providing an added layer of protection against unauthorized access.
• Two-factor authentication: Assembla supports two-factor authentication, adding an extra level of security to prevent unauthorized access. Plus, passwords are never stored directly in the database.
• Secure hosting: Assembla’s enterprise-grade cloud hosting ensures that your source code is stored in a secure and reliable environment. Physical security is provided by AWS staff in Ohio (USA), Frankfurt (Germany) and Mumbai (India).  
• SOC 2 Type II: Assembla is dedicated to maintaining the highest standards of source code security and has obtained AICPA SOC Type 2 Certification across all areas of our source code management platform.
• Multiple failovers: we operate from multiple redundant facilities, which guarantees server availability even in an outage scenario. Besides, we also have backups, replication, failover servers, and data retention for a month.

Source Code Security in Git, Perforce, and Subversion (SVN)

Assembla provides Git hosting, Perforce hosting, and SVN hosting. All of them have their pros and cons when it comes to built-in source code security, which is something you need to take into consideration. 

If you are worried about data loss, Git poses less risk because there are local copies. On the other hand, users can access the full repository copy and there’s no control for specific branches or files. This increases the attack surface, and protecting source code relies on each developer ensuring their endpoint is secure.

Perforce and SVN are different from Git because they’re centralized models. This allows organizations to have tighter control over the codebase, and users don’t necessarily have access to the full repo. Instead, you can issue permissions for a single file, branch or folder level to developers and subcontractors. However, there’s a single source of failure: if the central server is compromised, the entire source code security is at risk. 

Therefore, regardless of the VCS you choose, secure and stable hosting is key. At Assembla we comply with the highest security standards. Furthermore, we recommend following industry source code protection best practices such as strong authentication, encrypting, automated code scanning and regular auditing.  

Source code security in Git vs Perforce vs SVN

Source code security is essential to protect intellectual property, maintain software integrity, and prevent unauthorized access. At Assembla we take security seriously, so we provide data encrypting, 2FA, multiple failovers and are SOC 2 Type II-certified. If you are looking for a safe hosting solution, click here to start a free trial.