Rockwell Automation MicroLogix 1400

Rockwell Automation MicroLogix 1400 SNMP Credentials Vulnerability

CVE-2016-5645

Micrologix1400

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.

AFFECTED PRODUCTS

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

  • 1766-L32BWA
  • 1766-L32AWA
  • 1766-L32BXB
  • 1766-L32BWAA
  • 1766-L32AWAA
  • 1766-L32BXBA

IMPACT

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

BACKGROUND

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

The 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.

EXECUTION WITH UNNECESSARY PRIVILEGES

The MicroLogix 1400 utilizes this standard SNMP capability as its official mechanism for applying firmware updates to the product.

 

EXPLOITABILITY

This vulnerability could be exploited remotely.

MITIGATION

Due to the nature of this product’s 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 product’s “RUN” keyswitch setting to prevent unauthorized and undesired firmware update operations and other disruptive configuration changes.
  • Utilize proper network infrastructure controls, such as firewalls, to help ensure that SNMP requests from unauthorized sources are blocked. See KB496391d 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 manuale 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.