Buffer overflow is a common security vulnerability that occurs when a program tries to store more data in a buffer than it can hold. A buffer is a temporary storage area in a computer’s memory that is used to hold data while it is being processed. When a program tries to store more data in a buffer than it can hold, the extra data overflows into adjacent memory locations, which can cause the program to crash or behave unexpectedly.

Hackers can exploit buffer overflow vulnerabilities to execute malicious code on a computer. They can send specially crafted input to a program that causes it to overflow its buffer and overwrite adjacent memory locations with their own code. This can allow them to take control of the program and execute arbitrary commands on the computer.

To prevent buffer overflow vulnerabilities, programmers should always validate input data to ensure that it does not exceed the size of the buffer. They should also use secure coding practices, such as bounds checking and input validation, to prevent buffer overflow attacks.

In summary, buffer overflow is a security vulnerability that occurs when a program tries to store more data in a buffer than it can hold. Hackers can exploit this vulnerability to execute malicious code on a computer. Programmers can prevent buffer overflow vulnerabilities by validating input data and using secure coding practices.