The program can potentially fail to release a system resource. 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.Resource leaks have at least two common causes: confusion over which part of the program is responsible for releasing the resource. The following C# code executes a database query, processes the results returned by the database, and closes the allocated SqlConnection object. If this happens often enough, the database will run out of available cursors. If the process is long-lived, this can result in the process using up all of its file handles.”]
Source: https://owasp.org/www-community/vulnerabilities/Unreleased_Resource