Schneider Electric last week informed customers that patches have been made available for vulnerabilities in some Modicon controllers and several EcoStruxure products.
According to Schneider, Modicon M580, M340, Quantum and Premium controllers are affected by three denial-of-service (DoS) vulnerabilities.
The vendor says all three flaws are caused by “improper check for unusual or exceptional conditions.” Two of the vulnerabilities have been rated high severity, and one medium severity due to Schneider determining that the attack complexity is higher compared to the other two.
The DoS condition may be triggered when reading or writing specific memory blocks, or when reading data with an invalid index. The flaws can be exploited via Modbus TCP by an attacker who has network access to the affected controllers.
Industrial cybersecurity firm Nozomi Networks has been credited by Schneider for discovering the medium-severity flaw. Moreno Carcullo, Nozomi’s co-founder and CTO, told SecurityWeek that an attacker can exploit these vulnerabilities to crash the controller’s Ethernet module, requiring a cold restart (i.e. a physical reset) of the affected device.
It’s unclear if the vulnerabilities are remotely exploitable from the internet, but Shodan does show a couple of M580 and nearly 100 M340 internet-connected controllers.
Schneider Electric also informed customers last week of vulnerabilities in three of its EcoStruxure products. One of them is the Power SCADA Operation power monitoring and control software, which is designed to help organizations in the IT, healthcare, industrial and electro-intensive sectors maximize uptime.
The product is affected by a high-severity stack-based buffer overflow vulnerability that can be exploited to cause a server-side crash.
The EcoStruxure Geo SCADA Expert (ClearSCADA) product, which is designed for monitoring and controlling industrial processes, is affected by a high-severity insecure file permissions flaw that allows a local attacker with low privileges to delete or change database, settings or certificate files.
This vulnerability was identified by industrial cybersecurity firm Applied Risk, which published its own advisory last week.
Finally, Schneider Electric revealed that the EcoStruxure Control Expert programming software for Modicon programmable automation controllers is affected by a medium-severity vulnerability that can allow a hacker to bypass the authentication process between the software and the controller.