Emerson has a mitigation plan to help offset a stack-based buffer overflow in its ControlWave Micro Process Automation Controller, according to a report with ICS-CERT.
A family of SCADA RTUs, PLCs, PACs, and flow computers, ControlWave Micro [ProConOS v.4.01.280] – firmware: CWM v.05.78.00 and prior suffer from the remotely exploitable vulnerability, discovered by Younes Dragoni of Nozomi Networks.
Exploitation may possibly cause a halt of Ethernet functionality, requiring a cold start to restore the system as well as communications related to ControlWave Designer access. This can possibly result in a loss of system availability and disruption in communications with other connected devices.
No known public exploits specifically target this vulnerability. However, an attacker with low skill level could leverage the vulnerability.
A stack-based buffer overflow vulnerability caused by sending crafted packets on Port 20547 could force the PLC to change its state into halt mode.
CVE-2018-5452 is the case number assigned to this vulnerability, which has a CVSS v3 base score of 7.5.
The product sees use mainly in the energy and water and wastewater systems sectors. It also sees action on a global basis.
Emerson offers the following mitigation advice:
• Assess which ControlWave products in your organization have Ethernet connectivity.
• Upgrade the affected devices to firmware version 05.79.00 to correct this possible action. System firmware upgrade instructions are available in product documentation (ControlWave Micro Process Automation Controller Instruction Manual, part D301392X012).
• The resolution described is available only to the user when appropriately incorporated into the application running in ControlWave Micro firmware.
• Prior to upgrading the system firmware, always perform a full alarm and historical collection (archive files as well as audit logs).
The release notes and firmware upgrade are available to registered users.