How do buffer overflow attacks exploit system vulnerabilities?

Buffer overflow attacks occur when a program writes more data into a buffer (temporary storage area) than it can hold, thereby overwriting adjacent memory locations. This can lead to malicious code execution, system crashes, or privilege escalation.

To prevent buffer overflow attacks, various measures can be taken:

1. Input validation: Validate user input to ensure it does not exceed the buffer’s capacity.
2. Boundary checking: Enforce strict boundary limits to prevent data overflow.
3. Secure coding practices: Use secure coding techniques to avoid buffer overflows.
4. Address space layout randomization (ASLR): Randomize memory addresses to make it harder for attackers to predict where their malicious code will be located.
5. Data execution prevention (DEP): Mark certain memory regions as non-executable to prevent the execution of injected malicious code.
6. Stack canaries: Introduce random values known as canaries to detect buffer overflows before they cause harm.
7. Compiler protections: Use compilers with built-in security mechanisms to prevent buffer overflow vulnerabilities.

By implementing these preventive measures, the risk of buffer overflow attacks can be significantly reduced.