Schneider Electric has an upgrade plan for its Triconex Tricon, model 3008 that mitigates improper restriction of operations within the bounds of a memory buffer vulnerabilities, according to a report with ICS-CERT.
Successful exploitation of these vulnerabilities could misinform or control the Safety Instrumented System (SIS) which could result in arbitrary code execution, system shutdown, or the compromise of safety systems.
This vulnerability was discovered by NCCIC and Schneider Electric during the investigation of the HatMan malware.
A Safety Instrumented System, MP model 3008 firmware versions 10.0-10.4 suffer from the remotely exploitable vulnerabilities.
The system call reads directly from memory addresses within the control program area without any verification. Manipulating this data could allow attacker data to be copied anywhere within memory.
CVE-2018-8872 is the case number assigned to this vulnerability, which has a CVSS v3 base score of 10.0.
In addition, when a system call is made, registers are stored to a fixed memory location. Modifying the data in this location could allow attackers to gain supervisor-level access and control system states.
CVE-2018-7522 is the case number assigned to this vulnerability, which has a CVSS v3 base score of 7.9.
The product sees use in multiple sectors throughout the manufacturing automation industry. It also sees action on a global basis.
An attacker with low skill level could leverage the issues, however, HatMan malware specifically targets these vulnerabilities.
Schneider Electric recommends users upgrade their firmware to the latest 11.x version. If possible the users shodl contact Schneider Electric support for instructions.
The HatMan malware requires unrestricted access to the safety network via remote network or physical access. Additionally, the malware requires the Tricon key switch to be in the “PROGRAM” mode to successfully deploy its payload.
Schneider Electric continues to recommend users always implement the instructions in the “Security Considerations” section in the standard Triconex documentation, which includes the following:
• Ensure the cybersecurity features in Triconex solutions are always enabled
• Safety systems must always be deployed on isolated networks
• Physical controls should be in place so no unauthorized person would have access to the safety controllers, peripheral safety equipment, or the safety network
• All controllers should reside in locked cabinets and never be left in the “PROGRAM” mode
• All TriStation engineering workstations should be secured and never be connected to any network other than the safety network
• All methods of mobile data exchange with the isolated safety network such as CDs, USB drives, DVD’s, etc. should be scanned before use in the TriStation engineering workstations or any node connected to this network
• Laptops and PCs should always be properly verified to be virus and malware free before connecting to the safety network or any Triconex controller
• Operator stations should be configured to display an alarm whenever the Tricon key switch is in the “PROGRAM” mode