Detections
Analytics

Wago CODESYS V2 Web-Server Buffer Over-read (CVE-2021-34584)

critical Tenable OT Security Plugin ID 503323

Synopsis

The remote OT asset is affected by a vulnerability.

Description

Crafted web server requests can be utilised to read partial stack or heap memory or may trigger a denial-of- service condition due to a crash in the CODESYS V2 web server prior to V1.1.9.22.

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.

See Also

http://www.nessus.org/u?e6046ade

https://www.tenable.com/security/research/tra-2021-47

Plugin Details

Severity: Critical

ID: 503323

Version: 1.1

Type: remote

Family: Tenable.ot

Published: 9/9/2025

Updated: 9/9/2025

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 6.0

CVSS v2

Risk Factor: Medium

Base Score: 6.4

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

CVSS Score Source: CVE-2021-34584

CVSS v3

Risk Factor: Critical

Base Score: 9.1

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

Vulnerability Information

CPE: cpe:/o:wago:750-890_firmware, cpe:/o:wago:750-862_firmware, cpe:/o:wago:750-823_firmware, cpe:/o:wago:750-8203_firmware, cpe:/o:wago:750-8210_firmware, cpe:/o:wago:750-893_firmware, cpe:/o:wago:750-8206_firmware, cpe:/o:wago:750-889_firmware, cpe:/o:wago:750-885_firmware, cpe:/o:wago:750-8217_firmware, cpe:/o:wago:750-8211_firmware, cpe:/o:wago:750-8202_firmware, cpe:/o:wago:750-8204_firmware, cpe:/o:wago:750-8213_firmware, cpe:/o:wago:750-831_firmware, cpe:/o:wago:750-8212_firmware, cpe:/o:wago:750-891_firmware, cpe:/o:wago:750-8214_firmware, cpe:/o:wago:750-8208_firmware, cpe:/o:wago:750-881_firmware, cpe:/o:wago:750-829_firmware, cpe:/o:wago:750-852_firmware, cpe:/o:wago:750-832_firmware, cpe:/o:wago:750-880_firmware, cpe:/o:wago:750-8216_firmware, cpe:/o:wago:750-882_firmware, cpe:/o:wago:750-8207_firmware

Required KB Items: Tenable.ot/Wago

Exploit Ease: No known exploits are available

Patch Publication Date: 10/26/2021

Vulnerability Publication Date: 10/26/2021

Reference Information

CVE: CVE-2021-34584

CWE: 126