Siemens SIMATIC S7-1500 Improper Check for Unusual or Exceptional Conditions (CVE-2023-5678)

medium Tenable OT Security Plugin ID 502219

Synopsis

The remote OT asset is affected by a vulnerability.

Description

Issue summary: Generating excessively long X9.42 DH keys or checking excessively long X9.42 DH keys or parameters may be very slow. Impact summary: Applications that use the functions DH_generate_key() to generate an X9.42 DH key may experience long delays. Likewise, applications that use DH_check_pub_key(), DH_check_pub_key_ex() or EVP_PKEY_public_check() to check an X9.42 DH key or X9.42 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. While DH_check() performs all the necessary checks (as of CVE-2023-3817), DH_check_pub_key() doesn't make any of these checks, and is therefore vulnerable for excessively large P and Q parameters. Likewise, while DH_generate_key() performs a check for an excessively large P, it doesn't check for an excessively large Q. An application that calls DH_generate_key() or DH_check_pub_key() and supplies a key or parameters obtained from an untrusted source could be vulnerable to a Denial of Service attack.
DH_generate_key() and DH_check_pub_key() are also 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_pub_key_ex(), EVP_PKEY_public_check(), and EVP_PKEY_generate(). Also vulnerable are the OpenSSL pkey command line application when using the -pubcheck option, as well as the OpenSSL genpkey command line application. 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

Siemens has identified the following specific workarounds and mitigations that customers can apply to reduce the risk:

- Only build and run applications from trusted sources

Product-specific remediations or mitigations can be found in the section 'Affected Products and Solution' of the vendor advisory.

For more information, see the associated Siemens security advisory in HTML and CSAF.

Plugin Details

Severity: Medium

ID: 502219

Version: 1.7

Type: remote

Family: Tenable.ot

Published: 4/22/2024

Updated: 3/17/2025

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-2023-5678

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: 4/9/2024

Vulnerability Publication Date: 4/9/2024

Reference Information

CVE: CVE-2023-5678

CWE: 754

ICSA: 24-102-01, 25-044-09

Detections

Analytics