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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
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

        POSIX functions should not be called with arguments that trigger buffer overflows

        consistency - conventional
        reliability
        security
        Vulnerability
        • cwe
        • symbolic-execution
        • cert

        Some POSIX functions take one argument that is a buffer and another one that represents the size of the buffer. It is up to the developer to make sure the two arguments do match and that the size argument does not exceed the buffer’s size.

        Why is this an issue?

        How can I fix it?

        More Info

        When the size argument exceeds the actual size of the buffer, the memory management functions will either read or write data past the buffer memory boundary into adjacent memory. Because the memory might be uninitialized or contain other pieces of data, the behavior of the affected function can not be predicted and will likely trigger bugs.

        What is the potential impact?

        Buffer boundaries violations can lead to serious security issues.

        Information disclosure

        In some scenarios, insecure functions can lead to information disclosure. For instance, if an attacker can cause a buffer overread, they might be able to disclose data in memory that they’re not supposed to have access to. This could potentially allow them to access sensitive information, such as passwords or encryption keys. An example of a buffer overread is provided with the Heartbleed vulnerability. ==== Code execution

        In some cases, an attacker can craft input in a way that allows them to gain unauthorized access to your system. For example, they might be able to overwrite a function’s return address in memory, causing your program to execute code of the attacker’s choosing. This could potentially give the attacker full control over your system.

        Denial of service

        If an attacker can trigger a buffer overflow by providing oversized input, it can cause the program to crash. If the attacker repeats this process, it can continually disrupt the service, denying access to other users. This can be particularly damaging for services that require high availability, such as online platforms or databases.

        In some cases, the input might cause the program to enter an infinite loop or consume excessive memory, slowing down the system or even causing it to become unresponsive. This type of attack is known as a resource exhaustion DoS attack.

        Exceptions

        Functions related to sockets using the type socklen_t are not checked. This is because these functions are using a C-style polymorphic pattern using union. It relies on a mismatch between allocated memory and sizes of structures and it creates false positives.

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          Available Since
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