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Stack buffer overflow is a type of the more general programming malfunction known as buffer overflow (or buffer overrun). [1] Overfilling a buffer on the stack is more likely to derail program execution than overfilling a buffer on the heap because the stack contains the return addresses for all active function calls.
Visualization of a software buffer overflow. Data is written into A, but is too large to fit within A, so it overflows into B.. In programming and information security, a buffer overflow or buffer overrun is an anomaly whereby a program writes data to a buffer beyond the buffer's allocated memory, overwriting adjacent memory locations.
Canaries or canary words or stack cookies are known values that are placed between a buffer and control data on the stack to monitor buffer overflows. When the buffer overflows, the first data to be corrupted will usually be the canary, and a failed verification of the canary data will therefore alert of an overflow, which can then be handled, for example, by invalidating the corrupted data.
Developments were mostly theoretical until the Morris worm, which exploited a buffer overflow in fingerd. [5] The field of computer security developed quickly thereafter, escalating with multitudes of new attacks such as the return-to-libc attack and defense techniques such as the non-executable stack [6] and address space layout randomization.
Buffer overflow is one of the most common programming flaws exploited by computer viruses, causing serious computer security issues (e.g. return-to-libc attack, stack-smashing protection) in widely used programs. In some cases programs can also incorrectly access the memory before the start of a buffer.
Storage violation can, for instance, consist of reading from, writing to, or freeing storage not owned by the task. A common type of storage violation is known as a stack buffer overflow where a program attempts to exceed the limits set for its call stack. It can also refer to attempted modification of memory "owned" by another thread where ...
A buffer overflow; A stack overflow; Attempting to execute a program that does not compile correctly. (Some compilers [which?] will output an executable file despite the presence of compile-time errors.) In C code, segmentation faults most often occur because of errors in pointer use, particularly in C dynamic memory allocation.
A "return-to-libc" attack is a computer security attack usually starting with a buffer overflow in which a subroutine return address on a call stack is replaced by an address of a subroutine that is already present in the process executable memory, bypassing the no-execute bit feature (if present) and ridding the attacker of the need to inject their own code.