Siemens SCALANCE and RUGGEDCOM Devices Improper Input Validation (CVE-2024-49858)

medium Tenable OT Security Plugin ID 504581

Synopsis

The remote OT asset is affected by a vulnerability.

Description

efistub/tpm: Use ACPI reclaim memory for event log to avoid corruption The TPM event log table is a Linux specific construct, where the data produced by the GetEventLog() boot service is cached in memory, and passed on to the OS using an EFI configuration table. The use of EFI_LOADER_DATA here results in the region being left unreserved in the E820 memory map constructed by the EFI stub, and this is the memory description that is passed on to the incoming kernel by kexec, which is therefore unaware that the region should be reserved. Even though the utility of the TPM2 event log after a kexec is questionable, any corruption might send the parsing code off into the weeds and crash the kernel.

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-355557.html

https://support.industry.siemens.com/cs/ww/en/view/109988839/

Plugin Details

Severity: Medium

ID: 504581

Version: 1.1

Type: remote

Family: Tenable.ot

Published: 11/18/2025

Updated: 11/18/2025

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

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_xc-400_series_firmware, cpe:/o:siemens:scalance_xc-300_series_firmware, cpe:/o:siemens:scalance_xr-500wg_series_firmware, cpe:/o:siemens:scalance_xr-300_series_firmware, cpe:/o:siemens:scalance_xrm-300_series_firmware, cpe:/o:siemens:ruggedcom_rst2428p_firmware:3.2, cpe:/o:siemens:scalance_xcm-300_series_firmware, cpe:/o:siemens:scalance_xrh-300_series_firmware, cpe:/o:siemens:scalance_xr-500_series_firmware, cpe:/o:siemens:scalance_xch-300_series_firmware

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 8/12/2025

Vulnerability Publication Date: 8/12/2025

Reference Information

CVE: CVE-2024-49858

CWE: 20