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What causes a buffer to overflow in a program?
Every time your program solicits input (whether from a user, from a file, over a network, or by some other means), there is a potential to receive inappropriate data. For example, the input data might be longer than what you have reserved room for in memory.
Why is the EIP important in buffer overflow?
EIP offset is the exact value that gives us the information that how many bytes will fill the buffer and overflow into the return address (EIP). Controlling the EIP is a very crucial part of buffer overflow attacks because EIP is the register that will ultimately point to our malicious code so that it could be executed.
Where are function parameters stored in buffer overflow?
Above the EBP, function parameters are stored. Here a, b and c being the function parameters are stored above the EBP. All the local variables of a function are stored below the EBP. The Old %ebp is the value of the EBP of the previous function.
Can a buffer overflow be exploited on the heap?
In general, exploiting a buffer overflow on the heap is more challenging than exploiting an overflow on the stack. However, many successful exploits have involved heap overflows. There are two ways in which heap overflows are exploited: by modifying data and by modifying objects.
How to get data from a memory buffer?
To get the data into a std::string, use the constructor or assignment operator: You can even stick it in a std::stringstream so you can treat the data buffer like a file: Things work similarly for the MFC string class. To get the data from a string, you’ll need to copy it over.
How does a buffer manipulation function in C work?
Buffer manipulation functions in C work on the address of the memory block rather than the values inside the address. Example programs for memset(), memcpy(), memmove(), memcmp(), memicmp() and memchr() functions are given below.