Siemens SIMATIC and SCALANCE Devices Out-of-bounds Write (CVE-2024-9143)

medium Tenable OT Security Plugin ID 502894

Synopsis

The remote OT asset is affected by a vulnerability.

Description

Use of the low-level GF(2m) elliptic curve APIs with untrusted explicit values for the field polynomial can lead to out-of-bounds memory reads or writes. Impact summary: Out of bound memory writes can lead to an application crash or even a possibility of a remote code execution, however, in all the protocols involving Elliptic Curve Cryptography that we're aware of, either only named curves are supported, or, if explicit curve parameters are supported, they specify an X9.62 encoding of binary (GF(2m)) curves that can't represent problematic input values. Thus the likelihood of existence of a vulnerable application is low. In particular, the X9.62 encoding is used for ECC keys in X.509 certificates, so problematic inputs cannot occur in the context of processing X.509 certificates. Any problematic use-cases would have to be using an exotic curve encoding. The affected APIs include: EC_GROUP_new_curve_GF2m(), EC_GROUP_new_from_params(), and various supporting BN_GF2m_*() functions. Applications working with exotic explicit binary (GF(2m)) curve parameters, that make it possible to represent invalid field polynomials with a zero constant term, via the above or similar APIs, may terminate abruptly as a result of reading or writing outside of array bounds. Remote code execution cannot easily be ruled out. The FIPS modules in 3.3, 3.2, 3.1 and 3.0 are not affected by this issue.

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 has identified the following specific workarounds and mitigations users can apply to reduce risk:

- All affected products: Update to V3.0.0 or later version

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-769027 in HTML and CSAF.

Plugin Details

Severity: Medium

ID: 502894

File Name: tenable_ot_siemens_CVE-2024-9143.nasl

Version: 1.5

Type: remote

Family: Tenable.ot

Published: 2/24/2025

Updated: 2/14/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 2.2

CVSS v3

Risk Factor: Medium

Base Score: 4.3

Temporal Score: 3.8

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

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

Vulnerability Information

CPE: cpe:/o:siemens:scalance_wam763-1_%28us%29_firmware:3.0.0, cpe:/o:siemens:scalance_wam763-1_firmware:3.0.0, cpe:/o:siemens:scalance_wam766-1_%28us%29_firmware:3.0.0, cpe:/o:siemens:scalance_wam766-1_%28me%29_firmware:3.0.0, cpe:/o:siemens:scalance_wum763-1_firmware:3.0.0, cpe:/o:siemens:scalance_wub762-1_ifeatures_firmware:3.0.0, cpe:/o:siemens:scalance_wam766-1_firmware:3.0.0, cpe:/o:siemens:scalance_wam766-1_eec_%28us%29_firmware:3.0.0, cpe:/o:siemens:scalance_wum766-1_firmware:3.0.0, cpe:/o:siemens:scalance_wam766-1_eec_%28me%29_firmware:3.0.0, cpe:/o:siemens:simatic_s7-1500_cpu_firmware:3.1.5, cpe:/o:siemens:scalance_wab762-1_firmware:3.0.0, cpe:/o:siemens:scalance_wam766-1_eec_firmware:3.0.0, cpe:/o:siemens:scalance_wum766-1_%28me%29_firmware:3.0.0, cpe:/o:siemens:scalance_wub762-1_firmware:3.0.0, cpe:/o:siemens:scalance_wam763-1_%28me%29_firmware:3.0.0, cpe:/o:siemens:simatic_s7-1500_tm_mfp, cpe:/o:siemens:scalance_wum766-1_%28usa%29_firmware:3.0.0, cpe:/o:siemens:siplus_s7-1500_cpu_firmware:3.1.5, cpe:/o:siemens:scalance_wum763-1_%28us%29_firmware:3.0.0

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 12/12/2023

Vulnerability Publication Date: 12/12/2023

Reference Information

CVE: CVE-2024-9143

CWE: 787

ICSA: 25-044-09

Detections

Analytics