ICS Advisory (ICSA-16-021-01)

OVERVIEW

Independent researcher Maxim Rupp has identified an authorization bypass vulnerability in CAREL’s PlantVisor application. CAREL has confirmed that this vulnerability refers to the phased-out CAREL product PlantVisorEnhanced and is no longer supported.

This vulnerability could be exploited remotely.

AFFECTED PRODUCTS

CAREL reports that the vulnerability affects the following versions:

• PlantVisorEnhanced.

IMPACT

An attacker or unauthorized user can refer to the particular file and thus bypass authorization.

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.

BACKGROUND

CAREL is an Italy-based company that maintains offices in four countries around the world.

The affected product, PlantVisorEnhanced, is a web-based SCADA system. According to CAREL, PlantVisorEnhanced is deployed across several sectors including Commercial Facilities, Critical Manufacturing, and Energy. CAREL estimates that these products are used worldwide.

VULNERABILITY CHARACTERIZATION

VULNERABILITY OVERVIEW

As this vulnerability affects Internet Protocol-connected devices, an unauthorized user can refer to the particular file and thus bypass authorization.

CVE-2015-0867b has been assigned to this vulnerability. A CVSS v3 base score of 7.5 the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).c

VULNERABILITY DETAILS

EXPLOITABILITY

This vulnerability could be exploited remotely.

EXISTENCE OF EXPLOIT

No known public exploits specifically target this vulnerability.

DIFFICULTY

An attacker with a low skill would be able to exploit this vulnerability.

MITIGATION

PlantVisorEnhanced was replaced by PlantVisorPRO (new model) in 2007. Users should contact pvcustomercare@carel.com in order to receive the necessary files and details on how to perform the installation to avoid further security issues.

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.

• aCWE-20: Improper Input Validation, http://cwe.mitre.org/data/definitions/20.html, web site last accessed January 21. 2016.
• bNVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-0867, web site last accessed January 21. 2016.
• cCVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N, web site last accessed January 21. 2016.

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