20.3.13. Buffer Overflows

20.3. Application Attacks

Buffer Overflow Attack

When an attacker writes more data into a buffer (memory space) than it can hold, causing it to overflow into adjacent memory.

- Goal: Change how the application behaves—either by crashing it, or by gaining elevated privileges.

Buffer

A memory space allocated for storing a specific amount of data (e.g., 8 bytes).

Overflow

When more data is written than the buffer size, the extra data spills over into nearby memory.

Bounds Checking

Validate input length before storing in memory.

DEP

Data Execution Prevention

This tells certain memory areas, "You're just for data, no running code allowed!" so injected code can't work.

ASLR

Address Space Layout Randomization :

This constantly shuffles where important program parts are in memory, making it super hard for attackers to guess where to aim their harmful code.