Siemens SIMATIC S7-1500 Improper Encoding or Escaping of Output (CVE-2022-25235)

critical Tenable OT Security Plugin ID 503982

Synopsis

The remote OT asset is affected by a vulnerability.

Description

xmltok_impl.c in Expat (aka libexpat) before 2.4.5 lacks certain validation of encoding, such as checks for whether a UTF-8 character is valid in a certain context.

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

https://cert-portal.siemens.com/productcert/pdf/ssa-484086.pdf

https://cert-portal.siemens.com/productcert/html/ssa-398330.html

https://support.industry.siemens.com/cs/ww/en/view/109478459/

https://support.industry.siemens.com/cs/ww/en/view/109811169/

Plugin Details

Severity: Critical

ID: 503982

Version: 1.1

Type: remote

Family: Tenable.ot

Published: 11/13/2025

Updated: 11/13/2025

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/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:siemens:simatic_s7-1500_cpu_firmware:3.1.5, cpe:/o:siemens:siplus_s7-1500_cpu_firmware:3.1.5

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 6/14/2022

Vulnerability Publication Date: 6/14/2022

Reference Information

CVE: CVE-2022-25235

CWE: 116