Delta Electronics Delta Industrial Automation COMMGR

1. EXECUTIVE SUMMARY

• CVSS v3 7.3

• ATTENTION: Exploitable remotely/low skill level to exploit

• Vendor: Delta Electronics

• Equipment: Delta Industrial Automation COMMGR

• Vulnerability: Stack-based Buffer Overflow

2. RISK EVALUATION

Successful exploitation of this vulnerability may allow remote code execution, cause the application to crash, or cause a denial-of-service condition in the application server.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of Delta Industrial Automation COMMGR, a communication management software, and accompanying PLC simulators are affected:

• COMMGR Version 1.08 and prior.
  • DVPSimulator EH2, EH3, ES2, SE, SS2
  • AHSIM_5x0, AHSIM_5x1

3.2 VULNERABILITY OVERVIEW

3.2.1 STACK-BASED BUFFER OVERFLOW CWE-121

The application utilizes a fixed-length stack buffer where an unverified length value can be read from the network packets via a specific network port, causing the buffer to be overwritten. This may allow remote code execution, cause the application to crash, or result in a denial-of-service condition in the application server.

CVE-2018-10594 has been assigned to this vulnerability. A CVSS v3 base score of 7.3 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L).

3.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Commercial Facilities, Communications, Critical Manufacturing, Energy, Healthcare and Public Health
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: Taiwan

3.4 RESEARCHER

An anonymous researcher working with Trend Micro’s Zero Day Initiative reported this vulnerability to NCCIC.

4. MITIGATIONS

Delta Electronics has released COMMGR v1.09 to address this vulnerability and recommends users upgrade. The updated version can be downloaded at:

http://www.deltaww.com/Products/PluginWebUserControl/downloadCenterCounter.aspx?DID=2093&DocPath=1&hl=en-USl

Delta Electronics also recommends affected users apply application whitelists to allow only trusted communications via Ports 502 and 10002.

NCCIC recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. 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.

NCCIC reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

NCCIC 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 on the ICS-CERT website in the Technical Information Paper, ICS-TIP-12-146-01B–Targeted Cyber Intrusion Detection and Mitigation Strategies.

Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to NCCIC for tracking and correlation against other incidents.

NCCIC also recommends that users take the following measures to protect themselves from social engineering attacks:

• Do not click web links or open unsolicited attachments in email messages.
• Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
• Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.

No known public exploits specifically target this vulnerability.