CODESYS Control V3 - Exposed PKI folder

A vulnerability in the CODESYS Control runtime system allows low-privileged remote attackers to access the PKI folder via CODESYS protocol, enabling them to read and write certificates and keys. This exposes sensitive cryptographic data and allows unauthorized certificates to be trusted. However, all services remain available, only certificate based encryption and signing features are concerned. The issue affects systems using the optional CmpOpenSSL component for cryptographic operations.

Update 1.1.0, 01.09.2025: Updated remediation category - fixed SL runtimes are now available.

Unauthorized access to PKI files allows attackers to extract sensitive cryptographic keys and manipulate trusted certificates. This compromises system integrity, confidentiality and partially affects availability.

Update the following products to version 3.5.21.20.
* CODESYS Control RTE (SL)
* CODESYS Control RTE (for Beckhoff CX) SL
* CODESYS Control Win (SL)
* CODESYS HMI (SL)
* CODESYS Runtime Toolkit

Update the following products to version 4.17.0.0.
* CODESYS Control for BeagleBone SL
* CODESYS Control for emPC-A/iMX6 SL
* CODESYS Control for IOT2000 SL
* CODESYS Control for Linux ARM SL
* CODESYS Control for Linux SL
* CODESYS Control for PFC100 SL
* CODESYS Control for PFC200 SL
* CODESYS Control for PLCnext SL
* CODESYS Control for Raspberry Pi SL
* CODESYS Control for WAGO Touch Panels 600 SL
* CODESYS Virtual Control SL

The CODESYS Development System and the products available as CODESYS add-ons can be downloaded and installed directly with the CODESYS Installer or be downloaded from the CODESYS Store. Alternatively, as well as for all other products, you will find further information on obtaining the software update in the CODESYS Update area https://www.codesys.com/download/.

Following our general recommendation that the PKI should only be managed via the dedicated X.509 API or the corresponding online services of the CODESYS Control runtime system, the programmatic direct access via SysFile or SysDir operations or online access via the CODESYS file transfer services is denied after an update to a fixed product version. For compatibility reasons, the old behavior can be restored for applications that use these accesses via the following setting:
[CmpOpenSSL]
EnforceBlacklistOnPKIDir=0

However, CODESYS GmbH strongly recommends keeping the new default.