What kind of attack occurs due to storage of excess data in memory?

A buffer overflow attack occurs when a program writes more data to a block of memory, or buffer, than it was allocated for, leading to adjacent memory locations being overwritten. This flaw can be exploited by attackers to crash a program or execute malicious code. By inputting more data than a buffer can handle, the excess data spills over into adjacent memory areas, potentially overwriting critical data or control structures. This not only leads to unstable application behavior but may also open up pathways for executing arbitrary code, compromising security.

Buffer overflows are particularly dangerous because they can allow unauthorized access to sensitive data or control over a system. Since many programming languages, especially lower-level ones like C and C++, do not inherently check bounds on data input, they remain vulnerable to such attacks if developers do not implement proper input validation and memory management practices.