The WBM web application on firmwares prior to 03.02.02 and 03.01.07 on the WAGO PFC100 and PFC2000, respectively, runs on a lighttpd web server and makes use of the FastCGI module, which is intended to provide high performance for all Internet applications without the penalties of Web server APIs. However, the default configuration of this module appears to limit the number of concurrent php-cgi processes to two, which can be abused to cause a denial of service of the entire web server. This affects WAGO PFC200 Firmware version 03.00.39(12) and version 03.01.07(13), and WAGO PFC100 Firmware version 03.00.39(12) and version 03.02.02(14).

An exploitable regular expression without anchors vulnerability exists in the Web-Based Management (WBM) authentication functionality of WAGO PFC200 versions 03.00.39(12) and 03.01.07(13), and WAGO PFC100 version 03.00.39(12). A specially crafted authentication request can bypass regular expression filters, resulting in sensitive information disclosure.

An exploitable heap buffer overflow vulnerability exists in the iocheckd service I/O-Check functionality of WAGO PFC200 Firmware version 03.01.07(13), WAGO PFC200 Firmware version 03.00.39(12), and WAGO PFC100 Firmware version 03.00.39(12). A specially crafted set of packets can cause a heap buffer overflow, potentially resulting in code execution. An attacker can send unauthenticated packets to trigger this vulnerability.

ABB, Phoenix Contact, Schneider Electric, Siemens, WAGO - Programmable Logic Controllers, multiple versions. Researchers have found some controllers are susceptible to a denial-of-service attack due to a flood of network packets.