OVERVIEW

This updated advisory is a follow-up to the updated advisory titled ICSA-16-147-01A Environmental Systems Corporation Data Controllers Vulnerabilities that was published June 2, 2016, on the NCCIC/ICS-CERT web site.

Independent researcher Maxim Rupp has identified data controller vulnerabilities in the Environmental Systems Corporation (ESC) 8832 Data Controller. ESC acknowledged that Balazs Makany reported these vulnerabilities on February 18, 2015. ESC has stated the ESC 8832 Data Controller has no available code space to make any additional security patches; so, a firmware update is not possible. ESC has released an advisory that identifies compensating controls to reduce risk of exploitation of the reported vulnerabilities.

These vulnerabilities could be exploited remotely.

An exploit that targets these vulnerabilities is publicly available. A Metasploit module has been released that allows an attacker to hijack a valid session that is in progress by a legitimate user.

AFFECTED PRODUCTS

The following ESC 8832 Data Controller versions are affected:

• ESC 8832 Version 3.02 and earlier versions.

IMPACT

Successful exploitation of these vulnerabilities may allow attackers to perform administrative operations over the network without authentication.

Impact to individual organizations depends on many factors that are unique to each organization. ICS-CERT recommends that organizations evaluate the impact of these vulnerabilities based on their operational environment, architecture, and product implementation.

BACKGROUND

ESC is a US-based company that maintains offices in Austin, Texas.

The affected products, ESC 8832 Data Controller Versions 3.02 and earlier, are web-based SCADA systems. According to ESC, the 8832 Data Controller is deployed in the Energy Sector. ESC estimates that these products are used primarily in the United States.

VULNERABILITY CHARACTERIZATION

VULNERABILITY OVERVIEW

The device supports different accounts with distribution of system privileges. An attacker can gain access to functions, which are not displayed in the menu for the user by means of brute force of a parameter.

CVE-2016-4502e has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).f

VULNERABILITY DETAILS

EXPLOITABILITY

These vulnerabilities could be exploited remotely.

EXISTENCE OF EXPLOIT

There is a publicly available Metasploit module that allows an attacker to hijack a valid session.

DIFFICULTY

An attacker with a low skill would be able to exploit these vulnerabilities.

MITIGATION

ESC’s recommendation for mitigation is to upgrade the device. Alternatively, block Port 80 with a firewall in front of the device. Another alternative is to educate operators and users to not use the web interface for device management, because there are other means to manage the device. A security advisory is available to ESC users on the ESC support web site (login required):

www.envirosys.com.

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. 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.

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-287: Improper Authentication, http://cwe.mitre.org/data/definitions/287.html, web site last accessed December 22, 2016.
• b. NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-4501, web site last accessed December 22, 2016.
• c. CVSS 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:H/A:N, web site last accessed December 22, 2016.
• d. CWE-264: Permissions, Privileges, and Access Controls, http://cwe.mitre.org/data/definitions/264.html, web site last accessed May 26, 2016.
• e. NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-4502, web site last accessed June 02, 2016.
• f. CVSS 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 May 26, 2016.