CWE-763

Release of Invalid Pointer or Reference

Weakness Description

The product attempts to return a memory resource to the system, but it calls the wrong release function or calls the appropriate release function incorrectly.

This weakness can take several forms, such as: - The memory was allocated, explicitly or implicitly, via one memory management method and deallocated using a different, non-compatible function (CWE-762). - The function calls or memory management routines chosen are appropriate, however they are used incorrectly, such as in CWE-761.

Potential Mitigations

Implementation

Only call matching memory management functions. Do not mix and match routines. For example, when you allocate a buffer with malloc(), dispose of the original pointer with free().

Implementation

When programming in C++, consider using smart pointers provided by the boost library to help correctly and consistently manage memory.

Architecture and Design

Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, glibc in Linux provides protection against free of invalid pointers.

Architecture and Design

Use a language that provides abstractions for memory allocation and deallocation.

Testing

Use a tool that dynamically detects memory management problems, such as valgrind.

Common Consequences

IntegrityAvailabilityConfidentiality
Modify MemoryDoS: Crash, Exit, or RestartExecute Unauthorized Code or Commands

This weakness may result in the corruption of memory, and perhaps instructions, possibly leading to a crash. If the corrupted memory can be effectively controlled, it may be possible to execute arbitrary code.

Detection Methods

Fuzzing

Fuzz testing (fuzzing) is a powerful technique for generating large numbers of diverse inputs - either randomly or algorithmically - and dynamically invoking the code with those inputs. Even with random inputs, it is often capable of generating unexpected results such as crashes, memory corruption, or resource consumption. Fuzzing effectively produces repeatable test cases that clearly indicate bugs, which helps developers to diagnose the issues.

Effectiveness: High

Automated Dynamic Analysis

Use tools that are integrated during compilation to insert runtime error-checking mechanisms related to memory safety errors, such as AddressSanitizer (ASan) for C/C++ [REF-1518].

Effectiveness: Moderate

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