Siemens RUGGEDCOM RST2428P Improper Input Validation (CVE-2026-23238)

medium Tenable OT Security Plugin ID 505401

Synopsis

The remote OT asset is affected by a vulnerability.

Description

In the Linux kernel, the following vulnerability has been resolved:
romfs: check sb_set_blocksize() return value romfs_fill_super() ignores the return value of sb_set_blocksize(), which can fail if the requested block size is incompatible with the block device's configuration. This can be triggered by setting a loop device's block size larger than PAGE_SIZE using ioctl(LOOP_SET_BLOCK_SIZE, 32768), then mounting a romfs filesystem on that device. When sb_set_blocksize(sb, ROMBSIZE) is called with ROMBSIZE=4096 but the device has logical_block_size=32768, bdev_validate_blocksize() fails because the requested size is smaller than the device's logical block size. sb_set_blocksize() returns 0 (failure), but romfs ignores this and continues mounting. The superblock's block size remains at the device's logical block size (32768). Later, when sb_bread() attempts I/O with this oversized block size, it triggers a kernel BUG in folio_set_bh(): kernel BUG at fs/buffer.c:1582! BUG_ON(size > PAGE_SIZE); Fix by checking the return value of sb_set_blocksize() and failing the mount with -EINVAL if it returns 0.

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-253495.html

https://support.industry.siemens.com/cs/ww/en/view/110002573/

Plugin Details

Severity: Medium

ID: 505401

File Name: tenable_ot_siemens_CVE-2026-23238.nasl

Version: 1.1

Type: Remote

Family: Tenable.ot

Published: 6/18/2026

Updated: 6/18/2026

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:ruggedcom_rst2428p_firmware

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 6/2/2026

Vulnerability Publication Date: 2/26/2026

Reference Information

CVE: CVE-2026-23238

CWE: 20