OSIsoft PI AF Server Input Validation Vulnerability
ICSA： ICS Advisory (ICSA-16-166-02)
OSIsoft has identified an input validation vulnerability in its own PI AF Server. OSIsoft has produced a new version of PI AF Server 2016 to address this issue.
This vulnerability could be exploited remotely.
OSIsoft reports that the vulnerability affects the following products:
- PI AF Server prior to 2016, versions prior to 2.8.0
The issue exists in a component that ships with the PI AF Server. This component is used by other OSIsoft applications but is not normally used by user applications or users of the PI AF SDK or PI System Explorer. This component can be safely disabled following defensive measures without impacting other PI AF Server functionality with the condition that none of the listed OSIsoft applications are also being used.
An attacker who successfully exploits this vulnerability could cause the PI AF Server to stop responding.
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 headquarters in San Leandro, California, with global operations.
According to OSIsoft, the PI AF Server is a repository for asset-centric models, hierarchies, objects, and equipment. The PI System uses this core server technology to provide a framework for organizing and analyzing data. According to OSIsoft, PI AF is deployed across several critical infrastructure sectors. OSIsoft estimates that these products are used worldwide.
IMPROPER INPUT VALIDATIONa
A denial-of-service impact occurs when the PI AF Server improperly handles input while processing a message from an authenticated connection.
This vulnerability could be exploited remotely.
EXISTENCE OF EXPLOIT
No known public exploits specifically target this vulnerability.
An attacker with a low skill would be able to exploit this vulnerability.
OSIsoft recommends upgrading to PI AF Server 2016 to address this issue.
OSIsoft recommends using a host-based firewall to limit access to Port 5459 to only trusted workstations using PI SQL products such as PI OLEDB Enterprise. All versions of PI WebParts and PI Web Services will use PI OLEDB Enterprise for data access if it is configured as a provider for a relational data set. The following products access the PI AF Server 2016 over Port 5459 for search functionality:
- PI WebParts 2010 and earlier, and
- PI Coresight 2013 and earlier.
OSIsoft also recommends that access to the PI AF Server should be limited to only those users who need it.
For more information on this vulnerability, please refer to OSIsoft’s Security Bulletin AL00301 on this topic, which was released on OSIsoft’s web site on May 10, 2016:
ICS-CERT recommends that users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Specifically, users should:
- 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 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 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 (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 June 14, 2016.
- b. NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-4518 , 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, https://nvd.nist.gov/cvss.cfm?adv&calculator&version=2, web site last accessed June 14, 2016.