WAGO: Controller with CODESYS 2.3 Runtime Denial-of-Service

An authenticated attacker can send a malformed packet to trigger a device crash via the CODESYS V2 runtime commands parsing.
Update: 08.07.2024 release date of the updates has been changed.

Abusing these vulnerabilities an attacker can crash an affected product, which fully prevents the product to work as intended. After a complete restart the component works as expected.

If the PLC runtime is running, but you do not need it, you can deactivate the plc runtime programming port over the product settings in the web-based management. You can find this option under "Configuration > PLC Runtime Services > CODESYS 2 > communication enabled".

As general security measures strongly WAGO recommends:

1. Use general security best practices to protect systems from local and network attacks.
2. Do not allow direct access to the device from untrusted networks.
3. Update to the latest firmware according to the table in chapter solutions.
4. Industrial control systems (ICS) should not be directly accessible from the Internet, but should be protected by consistently applying the defense-in-depth strategy.

The BSI provides general information on securing ICS in the ICS Compendium (https://www.bsi.bund.de/SharedDocs/Downloads/EN/BSI/ICS/ICS-Security_compendium.pdf).

We recommend all affected users to update to the firmware version listed below:

PFC200 Family

Ethernet Controller 4th Generation Family

Ethernet Controller 3rd Generation Family

WAGO GmbH & Co. KG thanks the following parties for their efforts:

• CERT@VDE for coordination (see https://certvde.com )
• Abdelrahman Hassanien, Daniel dos Santos from Forescout