-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

===========================================================================
             AUSCERT External Security Bulletin Redistribution

                               ESB-2018.0835
                             Beckhoff TwinCAT
                               23 March 2018

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

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           Beckhoff TwinCAT
Publisher:         ICS-CERT
Operating System:  Windows
Impact/Access:     Administrator Compromise -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2018-7502  

Original Bulletin: 
   https://ics-cert.us-cert.gov/advisories/ICSA-18-081-02

- --------------------------BEGIN INCLUDED TEXT--------------------

Advisory (ICSA-18-081-02)

Beckhoff TwinCAT

Original release date: March 22, 2018

Legal Notice

All information products included in http://ics-cert.us-cert.gov are
provided "as is" for informational purposes only. The Department of Homeland
Security (DHS) does not provide any warranties of any kind regarding any
information contained within. DHS does not endorse any commercial product or
service, referenced in this product or otherwise. Further dissemination of this
product is governed by the Traffic Light Protocol (TLP) marking in the header.
For more information about TLP, see http://www.us-cert.gov/tlp/.

CVSS v3 7.8

ATTENTION: Low skill level to exploit.

Vendor: Beckhoff

Equipment: TwinCAT

Vulnerability: Untrusted Pointer Dereference

AFFECTED PRODUCTS

Beckhoff reports that the vulnerability affects the following TwinCAT PLC
products:

  o TwinCAT 3.1 Build 4022.4 or prior,
  o TwinCAT 2.11 R3 2259 or prior, and
  o TwinCAT 3.1 C++ / Matlab (TC1210/TC1220/TC1300/TC1320).

IMPACT

Successful exploitation of this vulnerability could allow local attackers to
escalate privileges.

MITIGATION

Beckhoff recommends users update to the newest version and recompile Matlab
modules after updating.

Please see Beckhoff Security Advisory 2018-001 at the following location for
more information:

https://download.beckhoff.com/download/Document/product-security/Advisories/
advisory-2018-001.pdf

NCCIC recommends users take defensive measures to minimize the risk of
exploitation of this vulnerability. Specifically, users should:

  o Restrict machine access to only those who need it.
  o Don't share usernames or passwords.
  o Monitor and respond to suspicious behavior.

NCCIC reminds organizations to perform proper impact analysis and risk
assessment prior to deploying defensive measures.

NCCIC also provides a section for control systems security recommended
practices on the ICS-CERT web page. Several recommended practices are available
for reading and download, including Improving Industrial Control Systems
Cybersecurity with Defense-in-Depth Strategies.

Additional mitigation guidance and recommended practices are publicly available
in the NCCIC Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber
Intrusion Detection and Mitigation Strategies, that is available for download
from the ICS-CERT website.

Organizations observing any suspected malicious activity should follow their
established internal procedures and report their findings to NCCIC for tracking
and correlation against other incidents.

No known public exploits specifically target this vulnerability. This
vulnerability is not exploitable remotely.

VULNERABILITY OVERVIEW

UNTRUSTED POINTER DEREFERENCE CWE-822

Several kernel drivers lack proper validation of user-supplied pointer values.
An attacker who is able to execute code on the target may be able to exploit
this vulnerability to obtain SYSTEM privileges.

CVE-2018-7502 has been assigned to this vulnerability. A CVSS v3 base score of
7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:L/UI:N/S:U/C:H
/I:H/A:H).

RESEARCHER

Steven Seeley of Source Incite reported this vulnerability to NCCIC.

BACKGROUND

Critical Infrastructure Sectors: Critical Manufacturing, Energy, Water and
Wastewater Systems

Countries/Areas Deployed: Worldwide

Company Headquarters Location: Germany

Contact Information

For any questions related to this report, please contact the NCCIC at:

Email: NCCICCUSTOMERSERVICE@hq.dhs.gov
Toll Free: 1-888-282-0870

For industrial control systems cybersecurity information:  
http://ics-cert.us-cert.gov 
or incident reporting:  
https://ics-cert.us-cert.gov/Report-Incident?

The NCCIC continuously strives to improve its products and services. You can
help by choosing one of the links below to provide feedback about this product.

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:

        https://www.auscert.org.au/bulletins/

===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967
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=wSQY
-----END PGP SIGNATURE-----