WAGO I/O-CHECK (CVE-2019-5073)

medium Tenable OT Security Plugin ID 500819


The remote OT asset is affected by a vulnerability.


An exploitable information exposure vulnerability exists in the iocheckd service I/O-Check functionality of WAGO PFC200 Firmware versions 03.01.07(13) and 03.00.39(12), and WAGO PFC100 Firmware version 03.00.39(12). A specially crafted set of packets can cause an external tool to fail, resulting in uninitialized stack data to be copied to the response packet buffer. An attacker can send unauthenticated packets to trigger this vulnerability.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.


The following text was originally created by the Cybersecurity and Infrastructure Security Agency (CISA). The original can be found at CISA.gov.

WAGO recommends updating to the latest firmware, FW 15 or above. WAGO has identified the following specific workarounds and mitigations users can apply to reduce the risk:

- The I/O-Check service protocol is only needed during installation and commissioning, not during normal operations.
- It is highly recommended to disable IP Port 6626 after commissioning.
- Disable unused TCP/UDP-ports.
- Restrict network access to the device.
- Do not directly connect the device to the Internet.

See Also



Plugin Details

Severity: Medium

ID: 500819

Version: 1.3

Type: remote

Family: Tenable.ot

Published: 2/14/2023

Updated: 11/6/2023

Supported Sensors: Nessus

Risk Information


Risk Factor: Low

Score: 2.2


Risk Factor: Medium

Base Score: 5

Temporal Score: 3.9

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS Score Source: CVE-2019-5073


Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:wago:pfc_100_firmware:03.00.39%2812%29, cpe:/o:wago:pfc_200_firmware:03.00.39%2812%29, cpe:/o:wago:pfc_200_firmware:03.01.07%2813%29

Required KB Items: Tenable.ot/Wago

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 12/18/2019

Vulnerability Publication Date: 12/18/2019

Reference Information

CVE: CVE-2019-5073

CWE: 200