Improper Resource Shutdown or Release
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.
The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.
Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.
The following method never closes the new file handle. Given enough time, the Finalize() method for BufferReader should eventually call Close(), but there is no guarantee as to how long this action will take. In fact, there is no guarantee that Finalize() will ever be invoked. In a busy environment, the Operating System could use up all of the available file handles before the Close() function is called.
The good code example simply adds an explicit call to the Close() function when the system is done using the file. Within a simple example such as this the problem is easy to see and fix. In a real system, the problem may be considerably more obscure.
This code attempts to open a connection to a database and catches any exceptions that may occur.
If an exception occurs after establishing the database connection and before the same connection closes, the pool of database connections may become exhausted. If the number of available connections is exceeded, other users cannot access this resource, effectively denying access to the application.
Under normal conditions the following C# code executes a database query, processes the results returned by the database, and closes the allocated SqlConnection object. But if an exception occurs while executing the SQL or processing the results, the SqlConnection object is not closed. If this happens often enough, the database will run out of available cursors and not be able to execute any more SQL queries.
The following C function does not close the file handle it opens if an error occurs. If the process is long-lived, the process can run out of file handles.
In this example, the program does not use matching functions such as malloc/free, new/delete, and new/delete to allocate/deallocate the resource.
In this example, the program calls the delete function on non-heap memory.
Weaknesses in this category are related to the CISQ Quality Measures for Efficiency. Presence of these weaknesses could reduce the efficiency of the software.
Weaknesses in this category are related to the CISQ Quality Measures for Security. Presence of these weaknesses could reduce the security of the software.
Weaknesses in this category are related to the CISQ Quality Measures for Reliability. Presence of these weaknesses could reduce the reliability of the software.
This view (slice) covers all the elements in CWE.
This view outlines the SMM representation of the Automated Source Code Data Protection Measurement specifications, as identified by the Consortium for Information & So...
CWE entries in this view (graph) may be used to categorize potential weaknesses within sources that handle public, third-party vulnerability information, such as the N...