Hash: SHA256

             AUSCERT External Security Bulletin Redistribution

    Rockwell Automation MicroLogix 1400 SNMP Credentials Vulnerability
                              12 August 2016


        AusCERT Security Bulletin Summary

Product:           Rockwell Automation MicroLogix 1400
Publisher:         ICS-CERT
Operating System:  Network Appliance
Impact/Access:     Execute Arbitrary Code/Commands -- Remote/Unauthenticated
Resolution:        Mitigation
CVE Names:         CVE-2016-5645  

Original Bulletin: 

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

Advisory (ICSA-16-224-01)

Rockwell Automation MicroLogix 1400 SNMP Credentials Vulnerability

Original release date: August 11, 2016

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/.


Cisco Talos, Cisco Systems, Inc.'s security intelligence and research group 
reported to Rockwell Automation that an undocumented and privileged Simple 
Network Management Protocol (SNMP) community string exists in MicroLogix 1400
programmable logic controllers (PLC). Rockwell Automation has released 
mitigation strategies to protect against this threat.

This vulnerability could be exploited remotely.


Rockwell Automation reports that the vulnerability affects all versions of the
following products:





    1766-L32AWAA, and



This vulnerability may allow an attacker to make unauthorized changes to the 
products configuration, including firmware updates.

Impact to individual organizations depends on many factors that are unique to
each organization. NCCIC/ICS-CERT recommends that organizations evaluate the 
impact of this vulnerability based on their operational environment, 
architecture, and product implementation.


Rockwell Automation, which is a US-based company, provides industrial 
automation control and information products worldwide across a wide range of 

The affected products, MicroLogix, are PLCs. According to Rockwell Automation,
these products are deployed across several sectors, including Chemical, 
Critical Manufacturing, Food and Agriculture, Water and Wastewater Systems, 
and others. Rockwell Automation estimates that these products are used in 
Germany, Czech Republic, France, Poland, Denmark, Hungary, Italy, and other 
countries in Europe, as well as in the United States, Korea, China, Japan, and
in Latin American countries.




SNMP is a standard protocol employed by many types of internet protocol based
products and allows centralized and remote device management capabilities. One
of the many standard SNMP capabilities enables users to manage the products 
firmware, including the capability of applying firmware updates to the 
product. The MicroLogix 1400 utilizes this standard SNMP capability as its 
official mechanism for applying firmware updates to the product.

CVE-2016-5645 [b] has been assigned to this vulnerability. A CVSS v3 base score 
of 7.3 has been calculated; the CVSS vector string is 
(CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L). [c]



This vulnerability could be exploited remotely.


No known public exploits specifically target this vulnerability.


An attacker with a low skill would be able to exploit this vulnerability.


Due to the nature of this products firmware update process, this capability 
cannot be removed from the product. Instead, mitigations are offered to reduce
risk of this capability being used by a malicious actor.

Rockwell Automation recommends that users using affected versions of the 
MicroLogix 1400 evaluate and deploy the risk mitigation strategies listed 
below. When possible, multiple strategies should be employed simultaneously.

Utilize the products RUN keyswitch setting to prevent unauthorized and 
undesired firmware update operations and other disruptive configuration 

Utilize proper network infrastructure controls, such as firewalls, to help 
ensure that SNMP requests from unauthorized sources are blocked. See KB496391 
[d] for more information on blocking access to SNMP services.

Disable the SNMP service on this product. The SNMP service is enabled by 
default. See Page 128 in the MicroLogix 1400 product manual [e] for detailed 
instructions on enabling and disabling SNMP.

Note: It will be necessary to re-enable SNMP to update firmware on this 
product. After the upgrade is complete, disable the SNMP service once again.

Note: Changing the SNMP community strings is not an effective mitigation.

Minimize network exposure for all control system devices and/or systems and 
ensure that they are not accessible from the Internet.

Locate control system networks and devices behind firewalls, and isolate them
from the business network.

When remote access is required, use secure methods, such as virtual private 
networks (VPNs), recognizing that VPNs may have vulnerabilities and should be
updated to the most current version available. Also recognize that a VPN is 
only as secure as the connected devices.

ICS-CERT reminds organizations to perform proper impact analysis and risk 
assessment prior to deploying defensive measures.

ICS-CERT also provides a section for control systems security recommended 
practices on the ICS-CERT web page at: 
http://ics-cert.us-cert.gov/content/recommended-practices. 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 ICSCERT Technical Information Paper, 
ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation 
Strategies, that is available for download from the ICS-CERT web site 

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

a. CWE-250: Execution with Unnecessary Privileges, 
http://cwe.mitre.org/data/definitions/250.html, web site last accessed August
11, 2016.

b. NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-5645, NIST 
uses this advisory to create the CVE web site report. This web site will be 
active sometime after publication of this advisory.

c. CVSS Calculator, 
web site last accessed August 11, 2016.

d. KB496391, 
https://rockwellautomation.custhelp.com/app/answers/detail/a_id/496391 (link 
is external), web site last accessed August 11, 2016.

e. MicroLogix 1400 Product Manual, 
(link is external), web site last accessed August 11, 2016.

Contact Information

For any questions related to this report, please contact ICS-CERT at:

Email: ics-cert@hq.dhs.gov (link sends e-mail)

Toll Free: 1-877-776-7585

International Callers: (208) 526-0900

For industrial control systems security information and incident reporting: 

ICS-CERT continuously strives to improve its products and services. You can 
help by choosing one of the links below to provide feedback about this 

- --------------------------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:


Australian Computer Emergency Response Team
The University of Queensland
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.
Comment: http://www.auscert.org.au/render.html?it=1967