WAGO I/O-CHECK Missing Authentication For Critical Function (CVE-2019-5078)

critical Tenable OT Security Plugin ID 500824

Synopsis

The remote OT asset is affected by a vulnerability.

Description

An exploitable denial of service 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 a denial of service, resulting in the device entering an error state where it ceases all network communications. 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.

Solution

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

https://talosintelligence.com/vulnerability_reports/TALOS-2019-0870

https://www.cisa.gov/news-events/ics-advisories/icsa-20-065-01

Plugin Details

Severity: Critical

ID: 500824

Version: 1.5

Type: remote

Family: Tenable.ot

Published: 2/14/2023

Updated: 9/4/2024

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 5.2

CVSS v2

Risk Factor: High

Base Score: 9.4

Temporal Score: 7

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

CVSS Score Source: CVE-2019-5078

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 7.9

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

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

Vulnerability Information

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

Required KB Items: Tenable.ot/Wago

Exploit Ease: No known exploits are available

Patch Publication Date: 12/18/2019

Vulnerability Publication Date: 12/18/2019

Reference Information

CVE: CVE-2019-5078

CWE: 306

ICSA: 20-065-01