Sielco Sistemi Winlog Buffer Overflow

This alert describes a buffer overflow vulnerability with proof-of-concept (PoC) exploit code affecting Sielco Sistemi Winlog Version 2.07.14, a supervisory control and data acquisition/human-machine interface (SCADA/HMI) product.

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Summary

ICS-CERT is aware of a public report of a buffer overflow vulnerability with proof-of-concept (PoC) exploit code affecting Sielco Sistemi Winlog Version 2.07.14, a supervisory control and data acquisition/human-machine interface (SCADA/HMI) product. According to this report, the vulnerability is exploitable by sending specially crafted requests to TCP/46824. This report was released by an independent security researcher Michael Messner without coordination with either the vendor or ICS-CERT.

ICS-CERT has notified Sielco of the report and has asked them to confirm the vulnerability and identify mitigations. ICS-CERT is issuing this alert to provide early notice of the report and identify baseline mitigations for reducing risks to these and other cybersecurity attacks.

The report included vulnerability details and PoC exploit code for the following vulnerability.

Please report any issues affecting control systems in critical infrastructure environments to ICS-CERT.

Winlog is a SCADA/HMI software package for the supervision of industrial and civil plants. It can connect to PLCs, controllers, motor drives, and I/O modules.

Follow-Up

ICS-CERT released a follow-up advisory ICSA-12-213-01 Sielco Sistemi Winlog Vulnerabilities to the ICS-CERT Web site on July 30, 2012.

Mitigation

ICS-CERT is currently coordinating with the vendor and security researcher to identify mitigations.

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. Control system devices should not directly face the Internet.a
• Locate control system networks and devices behind firewalls, and isolate them from the business network.
• If remote access is required, employ secure methods, such as Virtual Private Networks (VPNs), recognizing that VPN is only as secure as the connected devices.

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

The Control Systems Security Program (CSSP) also provides a recommended practices section for control systems on the US-CERT Web site. Several recommended practices are available for reading or download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

Organizations that observe 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. ICS-CERT ALERT, http://ics-cert.us-cert.gov/alerts/ICS-ALERT-10-301-01, Web site last accessed June 14, 2012. b. Control System