ICSA： ICS Advisory (ICSA-21-054-04)
1. EXECUTIVE SUMMARY
- CVSS v3 8.8
- ATTENTION: Exploitable remotely/low skill level to exploit
- Vendor: Ovarro
- Equipment: TBoxLT2 (All models), TBox MS-CPU32, TBox MS-CPU32-S2, TBox RM2 (All models), TBox TG2 (All models)
- Vulnerabilities: Code Injection, Incorrect Permission Assignment for Critical Resource, Uncontrolled Resource Consumption, Insufficiently Protected Credentials, Use of Hard-coded Cryptographic Key
2. REPOSTED INFORMATION
This updated advisory is a follow-up to the original advisory titled ICSA-21-054-04P Ovarro TBox that posted to the HSIN ICS library on February 23, 2021.
3. RISK EVALUATION
Successful exploitation of these vulnerabilities could result in remote code execution, which may cause a denial-of-service condition.
4. TECHNICAL DETAILS
4.1 AFFECTED PRODUCTS
The following versions of TBox, a remote terminal unit (RTU), are affected:
- TBoxLT2 (All models)
- TBox MS-CPU32
- TBox MS-CPU32-S2
- TBox RM2 (All models)
- TBox TG2 (All models)
- All versions prior to TWinSoft 12.4 and Firmware 1.46
4.2 VULNERABILITY OVERVIEW
The “ipk” package containing the configuration created by TWinSoft can be uploaded, extracted, and executed in the TBox, allowing malicious code execution.
The TBox proprietary Modbus file access functions allow attackers to read, alter, or delete the configuration file.
An attacker could use specially crafted invalid Modbus frames to crash the system.
TWinSoft uses the custom hardcoded user “TWinSoft” with a hardcoded key.
- CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing
- COUNTRIES/AREAS DEPLOYED: Worldwide
- COMPANY HEADQUARTERS LOCATION: United Kingdom
Uri Katz of Claroty reported these vulnerabilities to CISA.
Ovarro has released TWinSoft Version 12.4 and TBox firmware Version 1.46 to mitigate these vulnerabilities.
The latest version can be found on www.ovarro.com in the customer support section (service portal).
CISA 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 VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices.
CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices on the ICS webpage on us-cert.cisa.gov. 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 webpage on us-cert.cisa.gov 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 CISA for tracking and correlation against other incidents.
No known public exploits specifically target these vulnerabilities.