CWE-401 Detail

The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.

This is often triggered by improper handling of malformed data or unexpectedly interrupted sessions. In some languages, developers are responsible for tracking memory allocation and releasing the memory. If there are no more pointers or references to the memory, then it can no longer be tracked and identified for release.

Modes Of Introduction

Implementation :

Memory leaks have two common and sometimes overlapping causes:

• Error conditions and other exceptional circumstances
• Confusion over which part of the program is responsible for freeing the memory

Applicable Platforms

Language

Name: C (Undetermined)
Name: C++ (Undetermined)

Common Consequences

Observed Examples

Potential Mitigations

Phases : Implementation

Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.

For example, glibc in Linux provides protection against free of invalid pointers.

When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].

To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

Phases : Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Phases : Architecture and Design // Build and Compilation
The Boehm-Demers-Weiser Garbage Collector or valgrind can be used to detect leaks in 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 Static Analysis

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
Effectiveness : High

Vulnerability Mapping Notes

Justification : This CWE entry is at the Variant level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Comment : Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

NotesNotes

This is often a resultant weakness due to improper handling of malformed data or early termination of sessions.
"memory leak" has sometimes been used to describe other kinds of issues, e.g. for information leaks in which the contents of memory are inadvertently leaked (CVE-2003-0400 is one such example of this terminology conflict).

References

REF-18

The CLASP Application Security Process
Secure Software, Inc..
https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf

REF-390

How to Break Software Security
J. Whittaker, H. Thompson.

REF-391

Transitioning to ARC Release Notes
iOS Developer Library.
https://developer.apple.com/library/archive/releasenotes/ObjectiveC/RN-TransitioningToARC/Introduction/Introduction.html

REF-959

Automated Source Code Performance Efficiency Measure (ASCPEM)
Object Management Group (OMG).
https://www.omg.org/spec/ASCPEM/

Submission

Modifications