OSIsoft PI Interface for DNP3 Improper Input Validation
ICSA： ICS Advisory (ICSA-14-098-01)
Adam Crain of Automatak and Chris Sistrunk, Sr. Consultant for Mandiant, have identified an improper input validation vulnerability in the OSIsoft PI Interface for DNP3 product. OSIsoft has produced an update that mitigates this vulnerability. OSIsoft and Automatak have tested the new version to validate that it resolves the vulnerability
This vulnerability can be remotely exploited.
The following OSIsoft products are affected:
- All versions of the OSIsoft PI Interface for DNP3 prior to Version 126.96.36.199 are known to be affected.
The OSIsoft PI Interface for DNP3 (master station) can experience a denial-of-service (DoS) condition when it receives a specially crafted DNP3 response message from the outstation/slave on an IP-based network resulting in an unexpected shutdown of the interface. If the device is connected via a serial connection, the same attack can be accomplished with physical access to the outstation. The PI Interface for DNP3 must be restarted manually to clear the condition.
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.
OSIsoft is a US-based company that maintains its headquarters in San Leandro, California, with operations globally.
The affected product, PI Interface for DNP3, collects information from DNP3 compliant outstations. According to OSIsoft, PI Interface for DNP3 is deployed across electric and water utilities. OSIsoft estimates that these products are used primarily in North America with a small percentage in Asia and Europe.
As this vulnerability affects Internet Protocol-connected and serial-connected devices, two CVSS scores have been calculated.
IMPROPER INPUT VALIDATION-IP-BASEDa
The OSISoft PI Interface DNP Master Driver does not properly validate input. An attacker could cause the PI Interface for DNP3 to shut down unexpectedly with a specifically crafted TCP packet requiring a manual restart to clear the condition.
The following scoring is for IP-connected devices.
IMPROPER INPUT VALIDATION-SERIAL-BASEDd
The OSISoft PI Interface DNP Master Driver does not properly validate input. An attacker could cause the PI Interface for DNP3 to shut down unexpectedly requiring a manual restart to clear the condition.
The following scoring is for serial-connected devices.
The IP-based vulnerability could be exploited remotely.
The serial-based vulnerability is not exploitable remotely. Local access to the serial-based outstation is required.
EXISTENCE OF EXPLOIT
No known public exploits specifically target this vulnerability.
An attacker with a moderate skill could craft an IP packet that would be able to exploit the vulnerability for an IP-based device.
An attacker with a high skill could exploit the serial-based vulnerability because physical access to the device or some amount of social engineering is required.
OSIsoft has produced a software update that resolves these vulnerabilities. OSIsoft encourages customers using the affected product to upgrade to Version 188.8.131.52 or later. The software update can be found at the OSIsoft technical support web site:
The researchers suggest blocking DNP3 traffic from traversing onto business or corporate networks through the use of an Intrusion Prevention System or firewall with DNP3-specific rule sets to add an additional layer of protection.
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 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 Mitigation Strategies, that is available for download from the ICS-CERT web site (http://ics-cert.us-cert.gov/).
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-20: Improper Input Validation, http://cwe.mitre.org/data/definitions/20.html, web site last accessed April 08, 2014.
- b. NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2013-2809, 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, http://nvd.nist.gov/cvss.cfm?version=2&vector=AV:N/AC:M/Au:N/C:N/I:N/A:C, web site last accessed April 08, 2014.
- d. CWE-20: Improper Input Validation, http://cwe.mitre.org/data/definitions/20.html, web site last accessed April 08, 2014.
- e. NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2013-2828, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory.
- f. CVSS Calculator, http://nvd.nist.gov/cvss.cfm?version=2&vector=AV:L/AC:M/Au:N/C:N/I:N/A:C, web site last accessed April 08, 2014.