Siemens SIMATIC S7-1500 TM MFP BIOS Improper Input Validation (CVE-2021-42375)

medium Tenable OT Security Plugin ID 502953

Synopsis

The remote OT asset is affected by a vulnerability.

Description

An incorrect handling of a special element in Busybox's ash applet leads to denial of service when processing a crafted shell command, due to the shell mistaking specific characters for reserved characters. This may be used for DoS under rare conditions of filtered command input.

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-565386.pdf

https://cert-portal.siemens.com/productcert/pdf/ssa-419740.pdf

https://cert-portal.siemens.com/productcert/pdf/ssa-831302.pdf

https://support.industry.siemens.com/cs/ww/en/view/109815650/

https://support.industry.siemens.com/cs/ww/en/view/109945851/

https://support.industry.siemens.com/cs/document/109817007/

https://www.cisa.gov/news-events/ics-advisories/icsa-23-166-10

Plugin Details

Severity: Medium

ID: 502953

Version: 1.1

Type: remote

Family: Tenable.ot

Published: 2/25/2025

Updated: 2/25/2025

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v3

Risk Factor: Medium

Base Score: 4.1

Temporal Score: 3.7

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

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

Vulnerability Information

CPE: cpe:/o:siemens:scalance_m804pb_firmware:7.2, cpe:/o:siemens:scalance_m816-1_adsl-router_%28annex_a%29_firmware:7.2, cpe:/o:siemens:scalance_m874-3_firmware:7.2, cpe:/o:siemens:scalance_m876-4_%28nam%29_firmware:7.2, cpe:/o:siemens:scalance_s615_eec_firmware:7.2, cpe:/o:siemens:scalance_wam766-1_eec_%28us%29_firmware:2.0, cpe:/o:siemens:scalance_wum763-1_firmware:2.0, cpe:/o:siemens:scalance_wum766-1_%28eu%29_firmware:2.0, cpe:/o:siemens:scalance_m876-3_%28evdo%29_firmware:7.2, cpe:/o:siemens:scalance_wam766-1_%28us%29_firmware:2.0, cpe:/o:siemens:scalance_m816-1_adsl-router_%28annex_b%29_firmware:7.2, cpe:/o:siemens:scalance_s615_firmware:7.2, cpe:/o:siemens:ruggedcom_rm1224_lte%284g%29_eu_firmware:7.2, cpe:/o:siemens:scalance_m812-1_adsl-router_%28annex_a%29_firmware:7.2, cpe:/o:siemens:scalance_wam766-1_%28eu%29_firmware:2.0, cpe:/o:siemens:scalance_mum856-1_%28row%29_firmware:7.2, cpe:/o:siemens:scalance_m812-1_adsl-router_%28annex_b%29_firmware:7.2, cpe:/o:siemens:scalance_mum853-1_%28eu%29_firmware:7.2, cpe:/o:siemens:scalance_m874-2_firmware:7.2, cpe:/o:siemens:simatic_s7-1500_tm_mfp, cpe:/o:siemens:ruggedcom_rm1224_lte%284g%29_nam_firmware:7.2, cpe:/o:siemens:scalance_m876-4_%28eu%29_firmware:7.2, cpe:/o:siemens:scalance_wum766-1_%28us%29_firmware:2.0, cpe:/o:siemens:scalance_m826-2_shdsl-router_firmware:7.2, cpe:/o:siemens:scalance_mum856-1_%28eu%29_firmware:7.2, cpe:/o:siemens:scalance_m876-4_firmware:7.2, cpe:/o:siemens:scalance_m876-3_%28rok%29_firmware:7.2, cpe:/o:siemens:scalance_wam766-1_eec_%28eu%29_firmware:2.0, cpe:/o:siemens:scalance_wam763-1_firmware:2.0

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 3/14/2023

Vulnerability Publication Date: 3/14/2023

Reference Information

CVE: CVE-2021-42375

CWE: 20

ICSA: 23-166-10