Missing Release of File Descriptor or Handle after Effective Lifetime

File descriptors and handles are limited system resources that act as references to open files, network connections, or other I/O objects. When developers don't explicitly release them by calling close() or similar cleanup functions, these resources remain locked—even after the program stops using them. This creates a resource leak that accumulates over time, especially in long-running applications or loops. Attackers can exploit this weakness by repeatedly triggering the leak, eventually exhausting all available file descriptors on the system. This leads to a denial-of-service condition where legitimate processes—including the operating system itself—cannot open new files or network connections. The impact ranges from application crashes to full system instability, making proper resource lifecycle management essential for robust software.