Contents
What is a heap overflow attack?
Heap overflow attack – This type of attack targets data in the open memory pool known as the heap. Integer overflow attack – When an integer overflows, an arithmetic operation results in an integer (integer) that is too large to store the integer type; this may result in a buffer overflow.
How does a heap based buffer overflow work?
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). Buffer overflows generally lead to crashes.
What is Linux heap?
The heap is where all user-allocated memory is located. The heap grows up from a lower memory address to a higher memory address. Stack—whenever a program makes a function call, the current function’s state needs to be saved onto the stack.
How does the heap work?
The heap is memory set aside for dynamic allocation. Unlike the stack, there’s no enforced pattern to the allocation and deallocation of blocks from the heap; you can allocate a block at any time and free it at any time.
How are heap grooms used in heap exploitation?
Use a heap groom so the vulnerable object sits adjacent to a victim object. Use a conversion technique to construct an artificial use-after-free that is easier for the exploit developer to control. Use the UAF to build an information leak primitive, and leak kernel addresses, bypassing ASLR.
What happens when there is no free space on the heap?
If there are no free chunks available that can service the allocation request, the heap manager must instead construct a new chunk from scratch. To do this, the heap manager first looks at the free space at the end of the heap (sometimes called the “top chunk” or “remainder chunk”) to see if there is enough space there.
Is there a heap overflow vulnerability in iOS?
The iOS kernel exploit used in these attacks is built around a linear heap overflow vulnerability in a graphics driver.
How are heap allocations returned to the heap manager?
When these huge allocations are later returned to the heap manager via a call to free, the heap manager releases the entire mmaped region back to the system via munmap.
https://www.youtube.com/watch?v=A-Qf_Q_AeFw