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Can heap-based overflows perform code injection?
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program’s implicit security policy. Besides important user data, heap-based overflows can be used to overwrite function pointers that may be living in memory, pointing it to the attacker’s code.
Is it possible to perform a buffer overflow attack on the heap?
Heap overflow attack: A heap-based buffer overflow is where the buffer, to be overwritten, is allocated a large portion of additional memory. Exploitation is performed by corrupting stored data in ways that cause the application to overwrite internal structures.
Is it possible to execute code in heap space?
If the heap is executable, you can branch to that code. But some unix variants make the heap space non-executable, so as to make exploits of some security vulnerabilities such as buffer overflows more difficult (then even if you can inject code into a program, you might not be able to branch to it).
Can a heap overflow be used to execute arbitrary code?
A heap overflow in code for decoding a bitmap image allowed remote attackers to execute arbitrary code. A heap overflow vulnerability in a networking server allowed an attacker to execute arbitrary code by sending an HTTP POST request with a negative “Content-Length” header. Strings are a common form of input.
What happens when data is written to the heap?
A heap overflow is a form of buffer overflow; it happens when a chunk of memory is allocated to the heap and data is written to this memory without any bound checking being done on the data.
Where does execution occur in the stack and heap?
The answer is that execution occurs in the code section, which is neither stack nor heap. In a typical paged memory system, the code from a program file (e.g., a.exe in Windows) is loaded into executable but read-only pages. Additional writable (and executable) pages are allocated to the process for the stack and heap.