Wago PFC200 iocheckd service 'I/O-Check' cache Memory Corruption (CVE-2019-5186)

high Tenable OT Security Plugin ID 500922

Synopsis

The remote OT asset is affected by a vulnerability.

Description

An exploitable stack buffer overflow vulnerability vulnerability exists in the iocheckd service I/O-Check functionality of WAGO PFC 200. An attacker can send a specially crafted packet to trigger the parsing of this cache file.At 0x1eb9c the extracted interface element name from the xml file is used as an argument to /etc/config- tools/config_interfaces interface=<contents of interface element> using sprintf(). The destination buffer sp+0x40 is overflowed with the call to sprintf() for any interface values that are greater than 512-len(/etc/config-tools/config_interfaces interface=) in length.
Later, at 0x1ea08 strcpy() is used to copy the contents of the stack buffer that was overflowed sp+0x40 into sp+0x440. The buffer sp+0x440 is immediately adjacent to sp+0x40 on the stack. Therefore, there is no NULL termination on the buffer sp+0x40 since it overflowed into sp+0x440. The strcpy() will result in invalid memory access. An interface value of length 0x3c4 will cause the service to crash.

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

Solution

Refer to the vendor advisory.

Plugin Details

Severity: High

ID: 500922

Version: 1.2

Type: remote

Family: Tenable.ot

Published: 3/29/2023

Updated: 8/24/2023

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 4.4

Temporal Score: 3.4

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

CVSS Score Source: CVE-2019-5186

CVSS v3

Risk Factor: High

Base Score: 7

Temporal Score: 6.3

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

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

Vulnerability Information

CPE: cpe:/o:wago:pfc200_firmware:03.02.02%2814%29

Required KB Items: Tenable.ot/Wago

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 3/23/2020

Vulnerability Publication Date: 3/23/2020

Reference Information

CVE: CVE-2019-5186

CWE: 120

Detections

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