Backdoor in the X-Micro WLAN 11b Broadband Router
ALL VERSIONS ARE AFFECTED (1.6.0.1 too)
Previous bugreport's bugtraq id: 10095

FCC ID: RAFXWL-11BRRG
Firmware Version: 1.2.2, 1.2.2.3, 1.2.2.4, 1.6.0.0, 1.6.0.1
Remote: yes, easily expoitable
Type: administration password, which always works

The following username and password works in every case, even if you
set an other password on the web interface:
1.2.2, 1.2.2.3, 1.2.2.4, 1.6.0.0:
       Username: super
       Password: super

In 1.6.0.1:
       Username: 1502
       Password: 1502

Note: 1.2.2.4 is strictly identical to 1.2.2.3 (md5sum)

The webserver asks the username/password via HTTP auth headers.

By default the builtin webserver is listening on all network
interfaces (if connected to the internet, then it is accessible from
the internet too). Using the webinterface one can install new
firmware, download the old, view your password, etc., so he can:
 - make your board totally unusable, beyond repair
 - install viruses, trojans, sniffers, etc. in your router
 - get your password for your provider and maybe for your emails.

Possible fixes:
1. Set up portforwarding, and forward port 80, this way from the WAN
   interface an attack is impossible. But be aware, that anyone in your
   local LAN (possible over a wireless connection) can login to your
   router.

2. Upload a fixed firmware. I've made an unofficial (but fixed)
   one. You can download it from
   http://xmicro.risko.hu/own-firmwares/xm-11brrg-0.2/
   This firmware is unofficial. NO WARRANTY.
   This firmware also fix other bugs, for a list see:
     http://xmicro.risko.hu/own-firmwares/xm-11brrg-0.2/Changes
     (or below)
   The tool, which used to create the image also released under the
     GPL: http://xmicro.risko.hu/US8181-20040416.tar.gz
     DOCS: http://xmicro.risko.hu/

Optional cutie: 
  If you upload the webpages.bin from my xm-11brrg-0.2 directory, you
get a better topbar, with three nice penguins and a gnu! Screenshot at
http://xmicro.risko.hu/own-firmwares/xm-11brrg-0.2/screenshot.png!

Intresting things:
  Since my last bugtraq mail, Mr. Griswolds from X-Micro contacted me,
and told that what I did, is hurting the intellectual property of
X-Micro. I think, they didn't realized yet, that the base OS and tools
of the router is stolen from GPL projects. More about this things will
be written in an open letter to X-Micro, since this is not the subject
of this list.

Gergely Risko