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C#

C# static code analysis

Unique rules to find Bugs, Vulnerabilities, Security Hotspots, and Code Smells in your C# code

  • All rules 493
  • Vulnerability46
  • Bug88
  • Security Hotspot24
  • Code Smell335

  • Quick Fix 61
 
Tags
    Impact
      Clean code attribute
        1. Using unsafe code blocks is security-sensitive

           Security Hotspot
        2. Not specifying a timeout for regular expressions is security-sensitive

           Security Hotspot
        3. Hard-coded secrets are security-sensitive

           Security Hotspot
        4. Constructing arguments of system commands from user input is security-sensitive

           Security Hotspot
        5. Deserializing objects without performing data validation is security-sensitive

           Security Hotspot
        6. Disabling ASP.NET "Request Validation" feature is security-sensitive

           Security Hotspot
        7. Allowing requests with excessive content length is security-sensitive

           Security Hotspot
        8. Using publicly writable directories is security-sensitive

           Security Hotspot
        9. Using clear-text protocols is security-sensitive

           Security Hotspot
        10. Having a permissive Cross-Origin Resource Sharing policy is security-sensitive

           Security Hotspot
        11. Expanding archive files without controlling resource consumption is security-sensitive

           Security Hotspot
        12. Configuring loggers is security-sensitive

           Security Hotspot
        13. Using weak hashing algorithms is security-sensitive

           Security Hotspot
        14. Delivering code in production with debug features activated is security-sensitive

           Security Hotspot
        15. Disabling CSRF protections is security-sensitive

           Security Hotspot
        16. Searching OS commands in PATH is security-sensitive

           Security Hotspot
        17. Creating cookies without the "HttpOnly" flag is security-sensitive

           Security Hotspot
        18. Setting loose file permissions is security-sensitive

           Security Hotspot
        19. Using non-standard cryptographic algorithms is security-sensitive

           Security Hotspot
        20. Using pseudorandom number generators (PRNGs) is security-sensitive

           Security Hotspot
        21. Creating cookies without the "secure" flag is security-sensitive

           Security Hotspot
        22. Formatting SQL queries is security-sensitive

           Security Hotspot
        23. Hard-coded credentials are security-sensitive

           Security Hotspot
        24. Using hardcoded IP addresses is security-sensitive

           Security Hotspot

        Allowing requests with excessive content length is security-sensitive

        responsibility - trustworthy
        security
        Security Hotspot
        • cwe

        Rejecting requests with significant content length is a good practice to control the network traffic intensity and thus resource consumption in order to prevent DoS attacks.

        Ask Yourself Whether

        • size limits are not defined for the different resources of the web application.
        • the web application is not protected by rate limiting features.
        • the web application infrastructure has limited resources.

        There is a risk if you answered yes to any of those questions.

        Recommended Secure Coding Practices

        • For most of the features of an application, it is recommended to limit the size of requests to:
          • lower or equal to 8mb for file uploads.
          • lower or equal to 2mb for other requests.

        It is recommended to customize the rule with the limit values that correspond to the web application.

        Sensitive Code Example

        using Microsoft.AspNetCore.Mvc;
        
        public class MyController : Controller
        {
            [HttpPost]
            [DisableRequestSizeLimit] // Sensitive: No size  limit
            [RequestSizeLimit(10485760)] // Sensitive: 10485760 B = 10240 KB = 10 MB is more than the recommended limit of 8MB
            public IActionResult PostRequest(Model model)
            {
            // ...
            }
        
            [HttpPost]
            [RequestFormLimits(MultipartBodyLengthLimit = 10485760)] // Sensitive: 10485760 B = 10240 KB = 10 MB is more than the recommended limit of 8MB
            public IActionResult MultipartFormRequest(Model model)
            {
            // ...
            }
        }
        

        In Web.config:

        <configuration>
            <system.web>
                <httpRuntime maxRequestLength="81920" executionTimeout="3600" />
                <!-- Sensitive: maxRequestLength is expressed in KB, so 81920 KB = 80 MB  -->
            </system.web>
            <system.webServer>
                <security>
                    <requestFiltering>
                        <requestLimits maxAllowedContentLength="83886080" />
                        <!-- Sensitive: maxAllowedContentLength is expressed in bytes, so 83886080 B = 81920 KB = 80 MB  -->
                    </requestFiltering>
                </security>
            </system.webServer>
        </configuration>
        

        Compliant Solution

        using Microsoft.AspNetCore.Mvc;
        
        public class MyController : Controller
        {
            [HttpPost]
            [RequestSizeLimit(8388608)] // Compliant: 8388608 B = 8192 KB = 8 MB
            public IActionResult PostRequest(Model model)
            {
            // ...
            }
        
            [HttpPost]
            [RequestFormLimits(MultipartBodyLengthLimit = 8388608)] // Compliant: 8388608 B = 8192 KB = 8 MB
            public IActionResult MultipartFormRequest(Model model)
            {
            // ...
            }
        }
        

        In Web.config:

        <configuration>
            <system.web>
                <httpRuntime maxRequestLength="8192" executionTimeout="3600" />
                <!-- Compliant: maxRequestLength is expressed in KB, so 8192 KB = 8 MB  -->
            </system.web>
            <system.webServer>
                <security>
                    <requestFiltering>
                        <requestLimits maxAllowedContentLength="8388608" />
                        <!-- Compliant: maxAllowedContentLength is expressed in bytes, so 8388608 B = 8192 KB = 8 MB  -->
                    </requestFiltering>
                </security>
            </system.webServer>
        </configuration>
        

        See

        • OWASP - Top 10 2021 Category A5 - Security Misconfiguration
        • Owasp Cheat Sheet - Owasp Denial of Service Cheat Sheet
        • OWASP - Top 10 2017 Category A6 - Security Misconfiguration
        • CWE - CWE-770 - Allocation of Resources Without Limits or Throttling
        • CWE - CWE-400 - Uncontrolled Resource Consumption
        • Web.config - XML-formatted config file for IIS applications
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          in your IDE
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          on-premise CI
          Available Since
          9.1
        • SonarQube ServerAnalyze code in your
          on-premise CI
          Developer Edition
          Available Since
          9.1

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