Siemens SCALANCE and RUGGEDCOM Devices Incorrect Comparison (CVE-2024-9681)

medium Tenable OT Security Plugin ID 504760

Synopsis

The remote OT asset is affected by a vulnerability.

Description

When curl is asked to use HSTS, the expiry time for a subdomain might overwrite a parent domain's cache entry, making it end sooner or later than otherwise intended. This affects curl using applications that enable HSTS and use URLs with the insecure `HTTP://` scheme and perform transfers with hosts like `x.example.com` as well as `example.com` where the first host is a subdomain of the second host.
(The HSTS cache either needs to have been populated manually or there needs to have been previous HTTPS accesses done as the cache needs to have entries for the domains involved to trigger this problem.) When `x.example.com` responds with `Strict-Transport-Security:` headers, this bug can make the subdomain's expiry timeout *bleed over* and get set for the parent domain `example.com` in curl's HSTS cache. The result of a triggered bug is that HTTP accesses to `example.com` get converted to HTTPS for a different period of time than what was asked for by the origin server. If `example.com` for example stops supporting HTTPS at its expiry time, curl might then fail to access `http://example.com` until the (wrongly set) timeout expires. This bug can also expire the parent's entry *earlier*, thus making curl inadvertently switch back to insecure HTTP earlier than otherwise intended.

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: 504760

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: 5.0

CVSS v3

Risk Factor: Medium

Base Score: 6.5

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

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-2024-9681

CWE: 697