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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 315
  • Vulnerability13
  • Bug76
  • Security Hotspot19
  • Code Smell207

  • Quick Fix 19
 
Tags
    Impact
      Clean code attribute
        1. Hard-coded secrets are security-sensitive

           Security Hotspot
        2. "sprintf" should not be used

           Security Hotspot
        3. Changing working directories without verifying the success is security-sensitive

           Security Hotspot
        4. Setting capabilities is security-sensitive

           Security Hotspot
        5. Using "tmpnam", "tmpnam_s" or "tmpnam_r" is security-sensitive

           Security Hotspot
        6. Using "strncpy" or "wcsncpy" is security-sensitive

           Security Hotspot
        7. Using "strncat" or "wcsncat" is security-sensitive

           Security Hotspot
        8. Using "strcat" or "wcscat" is security-sensitive

           Security Hotspot
        9. Using "strlen" or "wcslen" is security-sensitive

           Security Hotspot
        10. Changing directories improperly when using "chroot" is security-sensitive

           Security Hotspot
        11. Using "strcpy" or "wcscpy" is security-sensitive

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

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

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

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

           Security Hotspot
        16. Setting loose POSIX file permissions is security-sensitive

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

           Security Hotspot
        18. Hard-coded passwords are security-sensitive

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

           Security Hotspot

        Setting loose POSIX file permissions is security-sensitive

        consistency - conventional
        security
        Security Hotspot
        • cwe
        • cert

        In Unix file system permissions, the "others" category refers to all users except the owner of the file system resource and the members of the group assigned to this resource.

        Granting permissions to this category can lead to unintended access to files or directories that could allow attackers to obtain sensitive information, disrupt services or elevate privileges.

        Ask Yourself Whether

        • The application is designed to be run on a multi-user environment.
        • Corresponding files and directories may contain confidential information.

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

        Recommended Secure Coding Practices

        The most restrictive possible permissions should be assigned to files and directories.

        Sensitive Code Example

        When creating a file or directory with permissions to "other group":

        open("myfile.txt", O_CREAT, S_IRWXU | S_IRWXG | S_IRWXO); // Sensitive: the process set 777 permissions to this newly created file
        
        mkdir("myfolder", S_IRWXU | S_IRWXG | S_IRWXO); // Sensitive: the process try to set 777 permissions to this newly created directory
        

        When explicitly adding permissions to "other group" with chmod, fchmod or filesystem::permissions functions:

        chmod("myfile.txt", S_IRWXU | S_IRWXG | S_IRWXO);  // Sensitive: the process set 777 permissions to this file
        
        fchmod(fd, S_IRWXU | S_IRWXG | S_IRWXO); // Sensitive: the process set 777 permissions to this file descriptor
        

        When defining the umask without read, write and execute permissions for "other group":

        umask(S_IRWXU | S_IRWXG); // Sensitive: the further files and folders will be created with possible permissions to "other group"
        

        Compliant Solution

        When creating a file or directory, do not set permissions to "other group":

        open("myfile.txt", O_CREAT, S_IRWXU | S_IRWXG); // Compliant
        
        mkdir("myfolder", S_IRWXU | S_IRWXG); // Compliant
        

        When using chmod, fchmod or filesystem::permissions functions, do not add permissions to "other group":

        chmod("myfile.txt", S_IRWXU | S_IRWXG);  // Compliant
        
        fchmod(fd, S_IRWXU | S_IRWXG); // Compliant
        

        When defining the umask, set read, write and execute permissions to other group:

        umask(S_IRWXO); // Compliant: further created files or directories will not have permissions set for "other group"
        

        See

        • OWASP - Top 10 2021 Category A1 - Broken Access Control
        • OWASP - Top 10 2021 Category A4 - Insecure Design
        • OWASP - Top 10 2017 Category A5 - Broken Access Control
        • OWASP File Permission
        • CWE - CWE-732 - Incorrect Permission Assignment for Critical Resource
        • CWE - CWE-266 - Incorrect Privilege Assignment
        • CERT, FIO06-C. - Create files with appropriate access permissions
        • STIG Viewer - Application Security and Development: V-222430 - The application must execute without excessive account permissions.
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