In cybersecurity, what is a buffer overflow?

A buffer overflow occurs when a program attempts to write more data into a buffer—a contiguous block of memory allocated for data storage—than it was meant to hold. This can lead to adjacent memory locations being overwritten, which may result in unpredictable behavior, crashes, or even the execution of malicious code.

In the context of cybersecurity, buffer overflows are significant vulnerabilities that attackers can exploit to compromise systems. By deliberately inputting data that exceeds the buffer’s capacity, they can manipulate the program's execution and can gain unauthorized access or control over the system. This understanding is crucial for developers and security professionals, as it highlights the importance of implementing proper bounds checking and error handling to mitigate such risks.

The other options touch on different aspects of data handling and system performance but do not accurately define the concept of a buffer overflow. Limiting data input or enhancing performance does not relate directly to the overflow issue itself, while using external storage for handling overflow is a different approach altogether, not the core definition of a buffer overflow.