Here is the closest I been able to come to inserting the "document".

xquery version "1.0-ml";
let $doc := xdmp:unquote( xdmp:filesystem-file("C:/xxeInjection.xml") )

return (
    $doc,
    xdmp:document-insert( "/xxeInjection.xml", $doc)
)

Here is the contents of the xxeInjection.xml file are exactly as you specify 
below.

However, when the file is loaded from the file system it is text and must be 
unquoted ...  xdmp:unquote() strips the invalid HTML DOCTYPE and we get:

<?xml version="1.0" encoding="UTF-8"?>
<foo>;</foo>

Could you please show us the code you used to insert the xxe injection 
"document" unmodified?

-Keith

From: Keith Breinholt
Sent: Wednesday, March 14, 2018 11:07 AM
To: general@developer.marklogic.com
Subject: RE: Marklogic XXE and XML Bomb prevention

Perhaps you could show the code that you used to insert the document into the 
database.

I, personally, cannot get your code to work for a number of reasons.  1) having 
both an xml processing statement and an HTML doctype is invalid.  2) Trying to 
assign the "document" to a variable throws an error because of #1. 3) If I try 
to put the "document" below into a file on the file system and load it I cannot 
use xdmp:document-insert() to insert the "document" into the database because 
there isn't a valid node.

There may be something I have overlooked so please share the code you used to 
insert this document into a database.

-Keith

From: 
general-boun...@developer.marklogic.com<mailto:general-boun...@developer.marklogic.com>
 
<general-boun...@developer.marklogic.com<mailto:general-boun...@developer.marklogic.com>>
 On Behalf Of Marcel de Kleine
Sent: Wednesday, March 14, 2018 6:43 AM
To: general@developer.marklogic.com<mailto:general@developer.marklogic.com>
Subject: [MarkLogic Dev General] Marklogic XXE and XML Bomb prevention

Hello,

We have noticed Marklogic is vulnerable to xxe (entity expansion) and xml bomb 
attacks. When loading an malicious document using xdmp:document-insert it won't 
catch these and cause either loading of unwanted external documents (xxe) and 
lockup of the system (xml bomb).

For example, if I load this document :
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [
   <!ELEMENT foo ANY >
   <!ENTITY xxe SYSTEM "file:///c:/text.xml" >]>
<foo>&xxe;</foo>

The file test.xml gets nicely added to the xml document.

See OWASP and others for examples.

This is clearly a xml processing issue so the question is : can we disable 
this? And if so, on what levels would this be possible. Best should be 
system-wide.
( And if you cannot disable this, I think this is something ML should address 
immediately.

Thank you in advance,
Marcel de Kleine, EPAM

Marcel de Kleine
Senior Software Engineer

Office: +31 20 241 6134 x 30530<tel:+31%2020%20241%206134;ext=30530>   Cell: 
+31 6 14806016<tel:+31%206%2014806016>   Email: 
marcel_de_kle...@epam.com<mailto:marcel_de_kle...@epam.com>
Delft, Netherlands   
epam.com<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.epam.com&d=DwMFAg&c=z0adcvxXWKG6LAMN6dVEqQ&r=wQ09nIebnRJGH1VgSesPfFnvXo10BKdu-taGZQaoghw&m=yiUEuOMjMBUR5ccv3Gi1vFMsW6pyEFhtMdzfpZtXd7g&s=a20FyQ4Tr_pZurrcjmEjQUs0A9Nd3NR48cC-wrqcKGA&e=>

CONFIDENTIALITY CAUTION AND DISCLAIMER
This message is intended only for the use of the individual(s) or entity(ies) 
to which it is addressed and contains information that is legally privileged 
and confidential. If you are not the intended recipient, or the person 
responsible for delivering the message to the intended recipient, you are 
hereby notified that any dissemination, distribution or copying of this 
communication is strictly prohibited. All unintended recipients are obliged to 
delete this message and destroy any printed copies.

_______________________________________________
General mailing list
General@developer.marklogic.com
Manage your subscription at: 
http://developer.marklogic.com/mailman/listinfo/general

Reply via email to