Siemens SIMATIC Devices Out-of-bounds Write (CVE-2025-21865)

medium Tenable OT Security Plugin ID 503686

Synopsis

The remote OT asset is affected by a vulnerability.

Description

gtp: Suppress list corruption splat in gtp_net_exit_batch_rtnl().
Commit eb28fd76c0a0 (gtp: Destroy device along with udp socket's netns dismantle.) added the for_each_netdev() loop in gtp_net_exit_batch_rtnl() to destroy devices in each netns as done in geneve and ip tunnels. However, this could trigger ->dellink() twice for the same device during ->exit_batch_rtnl().

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.

Siemens is preparing fixed versions and reports that currently, no fix is available.

As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for industrial security and following recommendations in the product manuals.

Additional information on industrial security by Siemens can be found on the Siemens industrial security webpage

For more information see the associated Siemens security advisory SSA-082556 in HTML and CSAF.

Plugin Details

Severity: Medium

ID: 503686

File Name: tenable_ot_siemens_CVE-2025-21865.nasl

Version: 1.3

Type: remote

Family: Tenable.ot

Published: 10/27/2025

Updated: 2/14/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v3

Risk Factor: Medium

Base Score: 5.5

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

Vulnerability Information

CPE: cpe:/o:siemens:simatic_s7-1500_cpu_firmware:3.1.5, cpe:/o:siemens:siplus_s7-1500_cpu_firmware, cpe:/o:siemens:simatic_s7-1500_tm_mfp

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 4/9/2024

Vulnerability Publication Date: 4/9/2024

Reference Information

CVE: CVE-2025-21865

CWE: 787

ICSA: 25-162-05

Detections

Analytics