OWASP Top 10 - code review plan for C#

 When performing a code review for C# applications with a focus on security, it is important to consider the OWASP Top 10 list. The OWASP Top 10 represents the most critical web application security risks. Here's a code review plan that you can follow:

1. Authentication and Authorization:

   - Review the implementation of authentication mechanisms (e.g., Forms Authentication, OAuth) to ensure secure user authentication.

   - Verify that authorization checks are performed correctly and consistently throughout the codebase.

2. Injection Attacks:

   - Identify any code that constructs SQL queries, XML, or OS commands using string concatenation and recommend the use of parameterized queries or prepared statements to prevent SQL injection.

   - Look for potential command injection or code injection vulnerabilities and suggest appropriate sanitization techniques.

3. Cross-Site Scripting (XSS):

   - Examine the code for any unvalidated user input that is directly rendered in web pages, and recommend input validation and output encoding techniques to prevent XSS attacks.

   - Check if the application properly handles and sanitizes user-generated content before rendering it on the page.

4. Insecure Direct Object References:

   - Ensure that sensitive data is not exposed or accessible directly through URLs or other client-supplied input.

   - Validate access controls to verify that users can only access the resources they are authorized to.

5. Security Misconfigurations:

   - Analyze the application's configuration files, deployment settings, and environment to identify any security misconfigurations.

   - Check for default or weak settings, unnecessary services, and open ports that may introduce vulnerabilities.

6. Sensitive Data Exposure:

   - Identify any instances where sensitive information, such as passwords or credit card numbers, is not properly protected.

   - Look for any weak encryption or hashing algorithms being used and suggest stronger alternatives.

7. Missing Function Level Access Control:

   - Review the code to ensure that all critical functions, such as administrative operations or sensitive data access, are protected with appropriate access controls.

   - Check for any missing authorization checks that could allow unauthorized users to perform privileged actions.

8. Cross-Site Request Forgery (CSRF):

   - Inspect the application's handling of requests and verify that appropriate anti-CSRF tokens are implemented to prevent CSRF attacks.

   - Check for consistent usage of these tokens across all relevant endpoints.

9. Using Components with Known Vulnerabilities:

   - Identify any third-party libraries or components used in the application and check for any known security vulnerabilities associated with them.

   - Recommend updating to the latest secure versions or finding suitable alternatives.

10. Unvalidated Redirects and Forwards:

    - Examine the code for any redirects or forwards that rely on user-supplied data, and ensure that they are properly validated and authorized.

    - Recommend using a whitelist approach for allowed redirections and avoid using user-supplied data for constructing URLs.

Remember to document your findings and provide actionable recommendations for each identified issue. Additionally, consider leveraging automated code review tools and security scanners to assist in the review process.