Siemens SIMATIC S7-1500 Improper Certificate Validation (CVE-2020-8286)

high Tenable OT Security Plugin ID 503991

Synopsis

The remote OT asset is affected by a vulnerability.

Description

The libcurl library versions 7.41.0 to and including 7.73.0 are vulnerable to an improper check for certificate revocation due to insufficient verification of the OCSP response. This vulnerability could allow an attacker to pass a revoked certificate as valid.

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: High

ID: 503991

Version: 1.2

Type: remote

Family: Tenable.ot

Published: 11/13/2025

Updated: 11/14/2025

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

Vulnerability Information

CPE: cpe:/o:siemens:simatic_s7-1500_cpu_firmware:3.1.5, cpe:/o:siemens:siplus_s7-1500_cpu_firmware:3.1.5

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 6/8/2021

Vulnerability Publication Date: 6/8/2021

Reference Information

CVE: CVE-2020-8286

CWE: 295

Detections

Analytics