Security_RNRF

Stack6 introduces return to .text to gain code execution. The metasploit tool “msfelfscan” can make searching for suitable instructions very easy, otherwise looking through objdump output will suffice. This level is at /opt/protostar/bin/stack7 Link - https://exploit.education/protostar/stack-seven/#source-code #include #include #include #include char *getpath() { char buffer[64]; unsigned int r..

Stack6 introduces return to .text to gain code execution. The metasploit tool “msfelfscan” can make searching for suitable instructions very easy, otherwise looking through objdump output will suffice. This level is at /opt/protostar/bin/stack7 Link - https://exploit.education/protostar/stack-seven/#source-code #include #include #include #include char *getpath() { char buffer[64]; unsigned int r..

Stack6 looks at what happens when you have restrictions on the return address. This level can be done in a couple of ways, such as finding the duplicate of the payload ( objdump -s will help with this), or ret2libc , or even return orientated programming. It is strongly suggested you experiment with multiple ways of getting your code to execute here. This level is at /opt/protostar/bin/stack6 Li..

Stack5 is a standard buffer overflow, this time introducing shellcode. This level is at /opt/protostar/bin/stack5 Hints At this point in time, it might be easier to use someone elses shellcode If debugging the shellcode, use \xcc (int3) to stop the program executing and return to the debugger remove the int3s once your shellcode is done. Link - https://exploit.education/protostar/stack-five/#sou..

Stack5 is a standard buffer overflow, this time introducing shellcode. This level is at /opt/protostar/bin/stack5 Hints At this point in time, it might be easier to use someone elses shellcode If debugging the shellcode, use \xcc (int3) to stop the program executing and return to the debugger remove the int3s once your shellcode is done. Link - https://exploit.education/protostar/stack-five/#sou..

Stack4 takes a look at overwriting saved EIP and standard buffer overflows. This level is at /opt/protostar/bin/stack4 Hints A variety of introductory papers into buffer overflows may help. gdb lets you do “run < input” EIP is not directly after the end of buffer, compiler padding can also increase the size. Link - https://exploit.education/protostar/stack-four/#source-code #include #include #in..

Stack3 looks at environment variables, and how they can be set, and overwriting function pointers stored on the stack (as a prelude to overwriting the saved EIP) Hints both gdb and objdump is your friend you determining where the win() function lies in memory. This level is at /opt/protostar/bin/stack3 Link - https://exploit.education/protostar/stack-three/#source-code #include #include #include..

Stack2 looks at environment variables, and how they can be set. This level is at /opt/protostar/bin/stack2 Link - https://exploit.education/protostar/stack-two/#source-code #include #include #include #include int main(int argc, char **argv) { volatile int modified; char buffer[64]; char *variable; variable = getenv("GREENIE"); if(variable == NULL) { errx(1, "please set the GREENIE environment va..

STACK ONE This level looks at the concept of modifying variables to specific values in the program, and how the variables are laid out in memory. This level is at /opt/protostar/bin/stack1 Hints If you are unfamiliar with the hexadecimal being displayed, “man ascii” is your friend. Protostar is little endian Link - https://exploit.education/protostar/stack-one/#source-code #include #include #inc..

STACK ZERO This level introduces the concept that memory can be accessed outside of its allocated region, how the stack variables are laid out, and that modifying outside of the allocated memory can modify program execution. This level is at /opt/protostar/bin/stack0 Link - https://exploit.education/protostar/stack-zero/#source-code #include #include #include int main(int argc, char **argv) { vo..