Siemens SCALANCE and RUGGEDCOM Improper Input Validation (CVE-2025-38086)

medium Tenable OT Security Plugin ID 505134

Synopsis

The remote OT asset is affected by a vulnerability.

Description

In the Linux kernel, the following vulnerability has been resolved:
net: ch9200: fix uninitialised access during mii_nway_restart In mii_nway_restart() the code attempts to call mii->mdio_read which is ch9200_mdio_read(). ch9200_mdio_read() utilises a local buffer called buff, which is initialised with control_read(). However buff is conditionally initialised inside control_read(): if (err == size) { memcpy(data, buf, size); } If the condition of err == size is not met, then buff remains uninitialised. Once this happens the uninitialised buff is accessed and returned during ch9200_mdio_read(): return (buff[0] | buff[1] << 8); The problem stems from the fact that ch9200_mdio_read() ignores the return value of control_read(), leading to uinit-access of buff. To fix this we should check the return value of control_read() and return early on error.

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/html/ssa-089022.html

https://support.industry.siemens.com/cs/ww/en/view/109997626/

Plugin Details

Severity: Medium

ID: 505134

File Name: tenable_ot_siemens_CVE-2025-38086.nasl

Version: 1.2

Type: remote

Family: Tenable.ot

Published: 2/10/2026

Updated: 2/11/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

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

CVSS Score Source: CVE-2025-38086

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

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

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

Vulnerability Information

CPE: cpe:/o:siemens:scalance_xrm334_%28230_v_ac%2c_8xfo%29_firmware:3.3, cpe:/o:siemens:scalance_xcm324_firmware:3.3, cpe:/o:siemens:scalance_xrm334_%2824v_dc%2c_2x10g%2c_24xsfp%2c_8xsfp%2b%29_firmware:3.3, cpe:/o:siemens:scalance_xrm334_%2824_v_dc%2c_8xfo%29_firmware:3.3, cpe:/o:siemens:scalance_xcm328_firmware:3.3, cpe:/o:siemens:scalance_xrm334_%28230_v_ac%2c_12xfo%29_firmware:3.3, cpe:/o:siemens:scalance_xrm334_%2824_v_dc%2c_12xfo%29_firmware:3.3, cpe:/o:siemens:scalance_xrm334_%28230v_ac%2c_2x10g%2c_24xsfp%2c_8xsfp%2b%29_firmware:3.3, cpe:/o:siemens:scalance_xrm334_%282x230v_ac%2c_2x10g%2c_24xsfp%2c_8xsfp%2b%29_firmware:3.3, cpe:/o:siemens:scalance_xrm334_%282x230_v_ac%2c_8xfo%29_firmware:3.3, cpe:/o:siemens:scalance_xrh334_%2824_v_dc%2c_8xfo%2c_cc%29_firmware:3.3, cpe:/o:siemens:ruggedcom_rst2428p_firmware:3.3, cpe:/o:siemens:scalance_xcm332_firmware, cpe:/o:siemens:scalance_xrm334_%282x230_v_ac%2c_12xfo%29_firmware:3.3, cpe:/o:siemens:scalance_xch328_firmware:3.3

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 1/28/2026

Vulnerability Publication Date: 6/28/2025

Reference Information

CVE: CVE-2025-38086

CWE: 20