Siemens SCALANCE W700 Inefficient Regular Expression Complexity (CVE-2023-3446)

medium Tenable OT Security Plugin ID 502874

Synopsis

The remote OT asset is affected by a vulnerability.

Description

Issue summary: Checking excessively long DH keys or parameters may be very slow. Impact summary: Applications that use the functions DH_check(), DH_check_ex() or EVP_PKEY_param_check() to check a DH key or DH parameters may experience long delays. Where the key or parameters that are being checked have been obtained from an untrusted source this may lead to a Denial of Service. The function DH_check() performs various checks on DH parameters. One of those checks confirms that the modulus ('p' parameter) is not too large. Trying to use a very large modulus is slow and OpenSSL will not normally use a modulus which is over 10,000 bits in length. However the DH_check() function checks numerous aspects of the key or parameters that have been supplied. Some of those checks use the supplied modulus value even if it has already been found to be too large. An application that calls DH_check() and supplies a key or parameters obtained from an untrusted source could be vulernable to a Denial of Service attack. The function DH_check() is itself called by a number of other OpenSSL functions. An application calling any of those other functions may similarly be affected. The other functions affected by this are DH_check_ex() and EVP_PKEY_param_check(). Also vulnerable are the OpenSSL dhparam and pkeyparam command line applications when using the '-check' option.
The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers 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

Refer to the vendor advisory.

Plugin Details

Severity: Medium

ID: 502874

Version: 1.2

Type: remote

Family: Tenable.ot

Published: 2/24/2025

Updated: 2/25/2025

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 2.2

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2023-3446

CVSS v3

Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.8

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

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

Vulnerability Information

CPE: cpe:/o:siemens:scalance_wab762-1_firmware:3.0.0, cpe:/o:siemens:scalance_wum766-1_%28me%29_firmware:3.0.0, cpe:/o:siemens:scalance_wum766-1_%28usa%29_firmware:3.0.0, cpe:/o:siemens:scalance_wam766-1_eec_%28me%29_firmware:3.0.0, cpe:/o:siemens:scalance_wam766-1_%28me%29_firmware:3.0.0, cpe:/o:siemens:scalance_wam766-1_eec_firmware:3.0.0, cpe:/o:siemens:simatic_s7-1500_cpu_firmware:3.1.0, cpe:/o:siemens:scalance_wum763-1_firmware:3.0.0, cpe:/o:siemens:scalance_wub762-1_firmware:3.0.0, cpe:/o:siemens:scalance_wam766-1_firmware:3.0.0, cpe:/o:siemens:siplus_s7-1500_cpu_firmware:3.1.0, cpe:/o:siemens:scalance_wam763-1_%28me%29_firmware:3.0.0, cpe:/o:siemens:scalance_wam766-1_eec_%28us%29_firmware:3.0.0, cpe:/o:siemens:scalance_wub762-1_ifeatures_firmware:3.0.0, cpe:/o:siemens:simatic_s7-1500_tm_mfp, 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_wum766-1_firmware:3.0.0, cpe:/o:siemens:scalance_wam766-1_%28us%29_firmware:3.0.0, cpe:/o:siemens:scalance_wum763-1_%28us%29_firmware:3.0.0

Required KB Items: Tenable.ot/Siemens

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 6/13/2023

Vulnerability Publication Date: 6/13/2023

Reference Information

CVE: CVE-2023-3446

CWE: 1333

ICSA: 25-044-09

Detections

Analytics