A buffer overflow is a type of software vulnerability that occurs when a program tries to write more data to a buffer (a temporary storage area in computer memory) than it can hold. When this happens, the extra data overflows into adjacent memory locations, which can cause the program to behave unpredictably or even crash.
For example, imagine a program that reads user input into a buffer that can hold up to 10 characters. If a user enters more than 10 characters, the program may try to write the extra characters to adjacent memory locations, which could overwrite important data or cause the program to crash.
Buffer overflows are a common type of security vulnerability and can be exploited by attackers to execute malicious code or take control of a system. Software developers can prevent buffer overflows by carefully validating user input and ensuring that buffers are sized appropriately to hold the data they are intended to store.