Control hijacking:
Control hijacking refers to a type of cyber attack where an attacker takes control of a program’s execution flow to manipulate its behavior. An example is a buffer overflow attack, where the attacker overflows a program’s buffer with excessive data, causing it to overwrite adjacent memory and eventually take control of the program’s execution.
Imagine a bookshelf representing a computer’s memory. Each book is a piece of information or code. A program reads from these books sequentially. Now, if an attacker puts too much information into one book (buffer overflow), it spills over to the next book, disrupting the original order. By carefully crafting this overflow, the attacker can manipulate the program to jump to a specific section of the shelf, giving them control over what the program does next.
Buffer overflow in Control Hijacking :
Imagine a buffer as a temporary storage area in a computer’s memory that holds data. This storage has a limited capacity, like a cup that can only hold a certain amount of liquid.
Now, a buffer overflow attack happens when too much data is poured into this buffer, overflowing it like pouring too much liquid into a cup. When the buffer overflows, it spills over into adjacent areas in the computer’s memory.
In the context of control hijacking, attackers take advantage of this overflow. They intentionally overflow the buffer with specific data that includes instructions for the computer to follow. This malicious data overwrites the memory beyond the intended buffer, manipulating the program’s execution path.
For example, let’s say there’s a program that takes user input and stores it in a buffer. If an attacker provides more data than the buffer can handle, it might overwrite critical information, changing how the program runs. This altered program execution could lead to unintended consequences, like exposing sensitive information or corrupting files.
There are two main types of buffer overflow attacks:
- Stack-based buffer overflows: These are common and involve overflowing a temporary memory region known as the stack, used during the execution of a function.
- Heap-based attacks: These are more challenging and involve overflowing the memory space allocated for a program beyond the memory used for current runtime operations.