SonarSource Rules
  • Products

    In-IDE

    Code Quality and Security in your IDE with SonarQube Ide

    IDE extension that lets you fix coding issues before they exist!

    Discover SonarQube for IDE

    SaaS

    Code Quality and Security in the cloud with SonarQube Cloud

    Setup is effortless and analysis is automatic for most languages

    Discover SonarQube Cloud

    Self-Hosted

    Code Quality and Security Self-Hosted with SonarQube Server

    Fast, accurate analysis; enterprise scalability

    Discover SonarQube Server
  • SecretsSecrets
  • ABAPABAP
  • AnsibleAnsible
  • ApexApex
  • AzureResourceManagerAzureResourceManager
  • CC
  • C#C#
  • C++C++
  • CloudFormationCloudFormation
  • COBOLCOBOL
  • CSSCSS
  • DartDart
  • DockerDocker
  • FlexFlex
  • GitHub ActionsGitHub Actions
  • GoGo
  • HTMLHTML
  • JavaJava
  • JavaScriptJavaScript
  • JSONJSON
  • JCLJCL
  • KotlinKotlin
  • KubernetesKubernetes
  • Objective CObjective C
  • PHPPHP
  • PL/IPL/I
  • PL/SQLPL/SQL
  • PythonPython
  • RPGRPG
  • RubyRuby
  • RustRust
  • ScalaScala
  • SwiftSwift
  • TerraformTerraform
  • TextText
  • TypeScriptTypeScript
  • T-SQLT-SQL
  • VB.NETVB.NET
  • VB6VB6
  • XMLXML
  • YAMLYAML
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

        Using unsafe code blocks is security-sensitive

        consistency - conventional
        security
        Security Hotspot

          Using unsafe code blocks can lead to unintended security or stability risks.

          unsafe code blocks allow developers to use features such as pointers, fixed buffers, function calls through pointers and manual memory management. Such features may be necessary for interoperability with native libraries, as these often require pointers. It may also increase performance in some critical areas, as certain bounds checks are not executed in an unsafe context.

          unsafe code blocks aren’t necessarily dangerous, however, the contents of such blocks are not verified by the Common Language Runtime. Therefore, it is up to the programmer to ensure that no bugs are introduced through manual memory management or casting. If not done correctly, then those bugs can lead to memory corruption vulnerabilities such as stack overflows. unsafe code blocks should be used with caution because of these security and stability risks.

          Ask Yourself Whether

          • There are any pointers or fixed buffers declared within the unsafe code block.

          There is a risk if you answered yes to the question.

          Recommended Secure Coding Practices

          Unless absolutely necessary, do not use unsafe code blocks. If unsafe is used to increase performance, then the Span and Memory APIs may serve a similar purpose in a safe context.

          If it is not possible to remove the code block, then it should be kept as short as possible. Doing so reduces risk, as there is less code that can potentially introduce new bugs. Within the unsafe code block, make sure that:

          • All type casts are correct.
          • Memory is correctly allocated and then released.
          • Array accesses can never go out of bounds.

          Sensitive Code Example

          public unsafe int SubarraySum(int[] array, int start, int end)  // Sensitive
          {
              var sum = 0;
          
              // Skip array bound checks for extra performance
              fixed (int* firstNumber = array)
              {
                  for (int i = start; i < end; i++)
                      sum += *(firstNumber + i);
              }
          
              return sum;
          }
          

          Compliant Solution

          public int SubarraySum(int[] array, int start, int end)
          {
              var sum = 0;
          
              Span<int> span = array.AsSpan();
              for (int i = start; i < end; i++)
                  sum += span[i];
          
              return sum;
          }
          

          See

          • CWE - CWE-787 - Out-of-bounds Write
          • Microsoft Learn - Unsafe code, pointer types, and function pointers
            Available In:
          • SonarQube IdeCatch issues on the fly,
            in your IDE
          • SonarQube CloudDetect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories
          • SonarQube Community BuildAnalyze code in your
            on-premise CI
            Available Since
            10.2
          • SonarQube ServerAnalyze code in your
            on-premise CI
            Developer Edition
            Available Since
            10.2

          © 2008-2025 SonarSource SA. All rights reserved.

          Privacy Policy | Cookie Policy | Terms of Use