Siemens SIMATIC Devices Out-of-bounds Write (CVE-2021-4090)

medium Tenable OT Security Plugin ID 503572

Synopsis

The remote OT asset is affected by a vulnerability.

Description

An out-of-bounds (OOB) memory write flaw was found in the NFSD in the Linux kernel. Missing sanity may lead to a write beyond bmval[bmlen-1] in nfsd4_decode_bitmap4 in fs/nfsd/nfs4xdr.c. In this flaw, a local attacker with user privilege may gain access to out-of-bounds memory, leading to a system integrity and confidentiality threat.

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: Medium

ID: 503572

Version: 1.2

Type: remote

Family: Tenable.ot

Published: 10/27/2025

Updated: 10/29/2025

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 5.2

CVSS v3

Risk Factor: Medium

Base Score: 5.3

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

Vulnerability Information

CPE: 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: 2/18/2022

Reference Information

CVE: CVE-2021-4090

CWE: 787

Detections

Analytics