Exploring bypasses for exploit mitigation technologies

Since the same types of vulnerabilities kept appearing, despite all the awareness and training for software developers on secure coding, new ways to reduce their impact and make them unusable for remote code execution have been introduced.

In particular, multiple exploit mitigation technologies were developed at various levels to make it hard to impossible for the attackers to successfully execute their shellcode. Let’s take a look at the most well-known mitigations that have been created for this purpose.

Data execution prevention (DEP/NX)

Data execution prevention is one of the earliest techniques that was introduced to protect against exploits and shellcode. The idea behind it is to stop the execution inside any memory page that doesn’t have EXECUTE permission. This technique can be supported by hardware that raises an exception once shellcode gets executed in the stack or in the heap (or any place in...