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 315
  • Vulnerability13
  • Bug76
  • Security Hotspot19
  • Code Smell207

  • Quick Fix 19
Filtered: 35 rules found
symbolic-execution
    Impact
      Clean code attribute
        1. The address of an automatic object should not be assigned to another object that may persist after the first object has ceased to exist

           Bug
        2. Variables should be initialized before use

           Bug
        3. Variables should not be accessed outside of their scope

           Bug
        4. Account validity should be verified when authenticating users with PAM

           Vulnerability
        5. Changing directories improperly when using "chroot" is security-sensitive

           Security Hotspot
        6. POSIX functions should not be called with arguments that trigger buffer overflows

           Vulnerability
        7. Server hostnames should be verified during SSL/TLS connections

           Vulnerability
        8. "pthread_mutex_t" should be unlocked in the reverse order they were locked

           Bug
        9. Only valid arguments should be passed to UNIX/POSIX functions

           Code Smell
        10. "pthread_mutex_t" should be properly initialized and destroyed

           Bug
        11. "pthread_mutex_t" should not be locked when already locked, or unlocked when already unlocked

           Bug
        12. Only valid arguments should be passed to stream functions

           Code Smell
        13. Using publicly writable directories is security-sensitive

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

           Security Hotspot
        15. Blocking functions should not be called inside critical sections

           Code Smell
        16. Return value of "setuid" family of functions should always be checked

           Code Smell
        17. Size of variable length arrays should be greater than zero

           Code Smell
        18. "mktemp" family of functions templates should have at least six trailing "X"s

           Code Smell
        19. Appropriate size arguments should be passed to "strncat" and "strlcpy"

           Code Smell
        20. Server certificates should be verified during SSL/TLS connections

           Vulnerability
        21. Weak SSL/TLS protocols should not be used

           Vulnerability
        22. Integral operations should not overflow

           Bug
        23. Parameter values should be appropriate

           Bug
        24. Stack allocated memory and non-owned memory should not be freed

           Bug
        25. Closed resources should not be accessed

           Bug
        26. Dynamically allocated memory should be released

           Bug
        27. Freed memory should not be used

           Bug
        28. Memory locations should not be released more than once

           Bug
        29. Memory access should be explicitly bounded to prevent buffer overflows

           Bug
        30. Zero should not be a possible denominator

           Bug
        31. XML parsers should not be vulnerable to XXE attacks

           Vulnerability
        32. "nonnull" parameters and return values of "returns_nonnull" functions should not be null

           Bug
        33. Null pointers should not be dereferenced

           Bug
        34. Resources should be closed

           Bug
        35. Unused assignments should be removed

           Code Smell

        Using publicly writable directories is security-sensitive

        intentionality - complete
        security
        Security Hotspot
        • cwe
        • symbolic-execution

        Operating systems have global directories where any user has write access. Those folders are mostly used as temporary storage areas like /tmp in Linux based systems. An application manipulating files from these folders is exposed to race conditions on filenames: a malicious user can try to create a file with a predictable name before the application does. A successful attack can result in other files being accessed, modified, corrupted or deleted. This risk is even higher if the application runs with elevated permissions.

        In the past, it has led to the following vulnerabilities:

        • CVE-2012-2451
        • CVE-2015-1838

        This rule raises an issue whenever it detects a hard-coded path to a publicly writable directory like /tmp (see examples bellow). It also detects access to environment variables that point to publicly writable directories, e.g., TMP and TMPDIR.

        • /tmp
        • /var/tmp
        • /usr/tmp
        • /dev/shm
        • /dev/mqueue
        • /run/lock
        • /var/run/lock
        • /Library/Caches
        • /Users/Shared
        • /private/tmp
        • /private/var/tmp
        • \Windows\Temp
        • \Temp
        • \TMP

        Ask Yourself Whether

        • Files are read from or written into a publicly writable folder
        • The application creates files with predictable names into a publicly writable folder

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

        Recommended Secure Coding Practices

        • Use a dedicated sub-folder with tightly controlled permissions
        • Use secure-by-design APIs to create temporary files. Such API will make sure:
          • The generated filename is unpredictable
          • The file is readable and writable only by the creating user ID
          • The file descriptor is not inherited by child processes
          • The file will be destroyed as soon as it is closed

        Sensitive Code Example

        #include <cstdio>
        // ...
        
        void f() {
          FILE * fp = fopen("/tmp/temporary_file", "r"); // Sensitive
        }
        
        #include <cstdio>
        #include <cstdlib>
        #include <sstream>
        // ...
        
        void f() {
          std::stringstream ss;
          ss << getenv("TMPDIR") << "/temporary_file"; // Sensitive
          FILE * fp = fopen(ss.str().c_str(), "w");
        }
        

        Compliant Solution

        #include <cstdio>
        #include <cstdlib>
        // ...
        
        void f() {
          FILE * fp = tmpfile(); // Compliant
        }
        

        See

        • OWASP - Top 10 2021 Category A1 - Broken Access Control
        • OWASP - Top 10 2017 Category A5 - Broken Access Control
        • OWASP - Top 10 2017 Category A3 - Sensitive Data Exposure
        • CWE - CWE-377 - Insecure Temporary File
        • CWE - CWE-379 - Creation of Temporary File in Directory with Incorrect Permissions
        • OWASP, Insecure Temporary File
        • STIG Viewer - Application Security and Development: V-222567 - The application must not be vulnerable to race conditions.
          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 ServerAnalyze code in your
          on-premise CI
          Developer Edition
          Available Since
          9.1

        © 2008-2025 SonarSource SA. All rights reserved.

        Privacy Policy | Cookie Policy | Terms of Use