CWE-404 – Improper Resource Shutdown or Release

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Description

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

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.

Modes of Introduction:

– Architecture and Design

 

Likelihood of Exploit: Medium

 

Related Weaknesses

CWE-664
CWE-405
CWE-619

 

Consequences

Availability, Other: DoS: Resource Consumption (Other), Varies by Context

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.

Confidentiality: Read Application Data

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

 

Potential Mitigations

Phase: Requirements

Description: 

Phase: Implementation

Description: 

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.

Phase: Implementation

Description: 

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

Phase: Implementation

Description: 

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

CVE References

  • CVE-1999-1127
    • Does not shut down named pipe connections if malformed data is sent.
  • CVE-2001-0830
    • Sockets not properly closed when attacker repeatedly connects and disconnects from server.
  • CVE-2002-1372
    • Return values of file/socket operations not checked, allowing resultant consumption of file descriptors.