buffer overflow short

What is buffer overflow?

A running program attempts to write data outside its buffer

How might a buffer overflow vulnerability be exploited?

Code can be inserted an executed in memory; if user input can only be 24 characters long they can insert code at 25

How does the stack grow in memory?

Down, pushing data decreases stack pointer and popping increases it

What is a stack pointer

A CPU register tracking the top of the stack

what items in order are saved on a stack when a c function call is made?

Return address, saved frame pointer, parameter values, all local variables

How does an attacker exploit a buffer overflow vulnerability?

Send the app a long string to overflow its buffer; overwrite return address using injected code

What are countermeasures against buffer overflow attack?

Check array bounds, non executable buffers, validate input, limit app privileges

Stack pointer is maintained by?

OS