CodeWrights GmbH HART DTM Vulnerability
OVERVIEW
Independent researcher Alexander Bolshev has identified an improper input validation vulnerability in CodeWrights GmbH HART Device Type Manager (DTM) libraries. CodeWrights GmbH produces DTM libraries for vendors of HART DTM products. CodeWrights GmbH has updated the libraries that mitigate this vulnerability. Using CodeWrights GmbH’s updated library for HART DTM, Emerson has tested the new library to validate that it resolves the vulnerability.
AFFECTED PRODUCTS
Any DTM written by CodeWrights GmbH DTMStudio prior to 1.5.151 is impacted. These libraries can be identified by a filename DDCH*Lib, where “*” is a wildcard string. Libraries prior to Version 1.4.181 are impacted.
CodeWrights GmbH’s customers include the following vendor companies:
- ABB,
- Berthold Technologies,
- Emerson,
- Endress+Hauser,
- Magnetrol, and
- Pepperl+Fuchs.
Other companies may be impacted and NCCIC/ICS-CERT will issue advisories for each vendor identified as remediation efforts are addressed. This advisory will be updated as necessary.
IMPACT
The vulnerability causes a buffer overflow in the HART component crashing the DTM component and the Field Device Tool (FDT) Frame application.
Impact to individual organizations depends on many factors that are unique to each organization. ICS-CERT recommends that organizations evaluate the impact of this vulnerability based on their operational environment, architecture, and product implementation.
BACKGROUND
CodeWrights GmbH is a German-based company that provides device integration and management solutions. The affected library is a component within the FDT/DTM application used to integrate HART devices.
CodeWrights GmbH supplies components that are used in DTMs of other vendors. HART DTM is deployed across several sectors including Chemical, Commercial Facilities, Critical Manufacturing, Energy, Food and Agriculture, Water and Wastewater Systems, and other sectors. CodeWrights GmbH estimates that these products are used worldwide.
VULNERABILITY CHARACTERIZATION
VULNERABILITY OVERVIEW
IMPROPER INPUT VALIDATIONCWE-20: Improper Input Validation, http://cwe.mitre.org/data/definitions/20.html, web site last accessed January 12, 2015.
By sending specially crafted response packets to the 4 mA to 20 mA current loop, the DTM component stops functioning and the FDT Frame application becomes unresponsive.
CVE-2014-9191NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-9191, web site last accessed January 12, 2015. has been assigned to this vulnerability. A CVSS v2 base score of 1.8 has been assigned; the CVSS vector string is (AV:A/AC:H/Au:N/C:N/I:N/A:P).CVSS Calculator, http://nvd.nist.gov/cvss.cfm?version=2&vector=AV:A/AC:H/Au:N/C:N/I:N/A:P, web site last accessed January 12, 2015.
VULNERABILITY DETAILS
EXPLOITABILITY
Access to the 4 mA to 20 mA HART current is required to exploit this vulnerability.
EXISTENCE OF EXPLOIT
No known public exploits specifically target this vulnerability.
DIFFICULTY
Crafting a working exploit for this vulnerability would be difficult. Compromised access to the 4 mA to 20 mA current loop is required in conjunction with a connected HART device modified to send crafted packets. The exploit also requires timing the spoofed response to crash the FDT/DTM components. This increases the difficulty of a successful exploit.
MITIGATION
CodeWrights GmbH has developed an updated library to address this vulnerability. These libraries are being provided to its customers (vendors) with current support agreements.
ICS-CERT recommends contacting the vendor if using HART DTM technology to determine if the products are vulnerable and what remediation steps should be taken.
ICS-CERT encourages asset owners to take additional defensive measures to protect against this and other cybersecurity risks.
- 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 remote 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 VPN is only as secure as the connected devices.
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. ICS-CERT reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
Additional mitigation guidance and recommended practices are publicly available in the ICS‑CERT 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 (www.ics-cert.org).
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.
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