Siemens SIMATIC and SCALANCE Products Encryption Strength (CVE-2023-0466)

medium Tenable OT Security Plugin ID 502325

Synopsis

The remote OT asset is affected by a vulnerability.

Description

The function X509_VERIFY_PARAM_add0_policy() is documented to implicitly enable the certificate policy check when doing certificate verification. However the implementation of the function does not enable the check which allows certificates with invalid or incorrect policies to pass the certificate verification.

As suddenly enabling the policy check could break existing deployments it was decided to keep the existing behavior of the X509_VERIFY_PARAM_add0_policy() function.

Instead the applications that require OpenSSL to perform certificate policy check need to use X509_VERIFY_PARAM_set1_policies() or explicitly enable the policy check by calling X509_VERIFY_PARAM_set_flags() with the X509_V_FLAG_POLICY_CHECK flag argument.

Certificate policy checks are disabled by default in OpenSSL and are not commonly used by applications.

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.

Plugin Details

Severity: Medium

ID: 502325

Version: 1.1

Type: remote

Family: Tenable.ot

Published: 7/23/2024

Updated: 7/23/2024

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 1.4

CVSS v3

Risk Factor: Medium

Base Score: 5.3

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

Vulnerability Information

CPE: cpe:/o:siemens:siplus_et_200sp_cp_1542sp-1_irc_tx_rail_firmware, cpe:/o:siemens:siplus_et_200sp_cp_1543sp-1_isec_firmware, cpe:/o:siemens:simatic_s7-1500_firmware, cpe:/o:siemens:scalance_xm416-4c_firmware, cpe:/o:siemens:scalance_xr524-8c_firmware, cpe:/o:siemens:simatic_cp_1543sp-1_firmware, cpe:/o:siemens:scalance_xm408-4c_firmware, cpe:/o:siemens:simatic_s7-1500_tm_mfp, cpe:/o:siemens:simatic_cp_1542sp-1_firmware, cpe:/o:siemens:siplus_et_200sp_cp_1543sp-1_isec_tx_rail_firmware, cpe:/o:siemens:scalance_xr526-8c_firmware, cpe:/o:siemens:scalance_xm408-8c_firmware, cpe:/o:siemens:scalance_xr552-12m_firmware, cpe:/o:siemens:simatic_cp_1542sp-1_irc_firmware, cpe:/o:siemens:scalance_xr528-6m_firmware

Required KB Items: Tenable.ot/Siemens

Patch Publication Date: 1/10/2023

Vulnerability Publication Date: 1/10/2023

Reference Information

CVE: CVE-2023-0466

CWE: 326

Detections

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