How Buffer Overrun Works?

A buffer overflow, or buffer overrun, occurs when more data is put into a fixed-length buffer than the buffer can handle. The extra information, which has to go somewhere, can overflow into adjacent memory space, corrupting or overwriting the data held in that space.

Why do buffer overflows happen what is the main cause?

The most common reason why buffer overflow attacks work is because applications fail to manage memory allocations and validate input from the client or other processes. Applications developed in C or C++ should avoid dangerous standard library functions that are not bounds-checked, such as gets, scanf and strcpy.

What is a buffer overflow and how is it used against a Web server?

A buffer overflow occurs when a program tries to write too much data in a fixed length block of memory (a buffer). Buffer overflows can be used by attackers to crash a web-server or execute malicious code.