by manipulating a buffer overflow an attacker can jump
Buffer overflow If the address of the user-supplied data used to affect the stack buffer overflow is unpredictable, exploiting a stack buffer overflow to cause remote code execution becomes much more difficult. One technique that can be used to exploit such a buffer overflow is called "trampolining". In that technique, an attacker will find a pointer to the vulnerable stack buffer, and compute the location of their shellcode relative to that pointer. Then, they will use the overwrite to jump to an instruction already in memory which will make a second jump, this time relative to the pointer; that second jump will branch execution into the shellcode. Suitable instructions are often present in large code. The Metasploit Project, for example, maintains a database of suitable opcodes, though it lists only those found in the Windows operating system.[3]