COMMON WEAKNESS ENUMERATIONDraft

CWE-404

Improper Resource Shutdown or Release

The product does not release or incorrectly releases a resource before it is made available for re-use.

Soyutlama

Class

Yapı

Simple

Sömürü İhtimali

Medium

Problemi anla

Problem nedir?

The product does not release or incorrectly releases a resource before it is made available for re-use.

Genişletilmiş açıklama

When a resource is created or allocated, the developer is responsible for properly releasing the resource as well as accounting for all potential paths of expiration or invalidation, such as a set period of time or revocation.

Kök neden

Problem nasıl ve ne zaman oluşur?

Yaşam döngüsü evresi

Implementation

Risk

Başarılı sömürü neye yol açar?

DoS: Resource Consumption (Other)Varies by Context

Etkilenen güvenlik alanları: Availability, Other

Most unreleased resource issues result in general software reliability problems, but if an attacker can intentionally trigger a resource leak, the attacker might be able to launch a denial of service attack by depleting the resource pool.
Read Application Data

Etkilenen güvenlik alanları: Confidentiality

When a resource containing sensitive information is not correctly shutdown, it may expose the sensitive data in a subsequent allocation.

Savunma

Nasıl önlenir ve çözülür?

Requirements

Language Selection

Detay
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, languages such as Java, Ruby, and Lisp perform automatic garbage collection that releases memory for objects that have been deallocated.

Implementation

Uygulama aşaması savunması

Detay
It is good practice to be responsible for freeing all resources you allocate and to be consistent with how and where you free memory in a function. If you allocate memory that you intend to free upon completion of the function, you must be sure to free the memory at all exit points for that function including error conditions.

Implementation

Uygulama aşaması savunması

Detay
Memory should be allocated/freed using matching functions such as malloc/free, new/delete, and new[]/delete[].

Implementation

Uygulama aşaması savunması

Detay
When releasing a complex object or structure, ensure that you properly dispose of all of its member components, not just the object itself.

Doğrulama

Nasıl tespit edilir?

Automated Dynamic Analysis

Moderate
This weakness can be detected using dynamic tools and techniques that interact with the software using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The software's operation may slow down, but it should not become unstable, crash, or generate incorrect results. Resource clean up errors might be detected with a stress-test by calling the software simultaneously from a large number of threads or processes, and look for evidence of any unexpected behavior. The software's operation may slow down, but it should not become unstable, crash, or generate incorrect results.

Manual Dynamic Analysis

Identify error conditions that are not likely to occur during normal usage and trigger them. For example, run the product under low memory conditions, run with insufficient privileges or permissions, interrupt a transaction before it is completed, or disable connectivity to basic network services such as DNS. Monitor the software for any unexpected behavior. If you trigger an unhandled exception or similar error that was discovered and handled by the application's environment, it may still indicate unexpected conditions that were not handled by the application itself.

Automated Static Analysis

High
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.)