Siemens SIMATIC Controller Web Servers Uncaught Exception (CVE-2020-15796)

high Tenable OT Security Plugin ID 500454

Synopsis

The remote OT asset is affected by a vulnerability.

Description

A vulnerability has been identified in SIMATIC ET 200SP Open Controller (incl. SIPLUS variants) (V20.8), SIMATIC S7-1500 Software Controller (V20.8). The web server of the affected products contains a vulnerability that could allow a remote attacker to trigger a denial-of-service condition by sending a specially crafted HTTP request.

This plugin only works with Tenable.ot. Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

The following text was originally created by the Cybersecurity and Infrastructure Security Agency (CISA). The original can be found at CISA.gov.

Siemens has released updates for the affected products and recommends updating to the latest version:

- SIMATIC ET 200SP Open Controller (incl. SIPLUS variants): Update to v21.8
- SIMATIC S7-1500 Software Controller: Update to v21.8

Siemens notes that if the PC Station web server does not restart automatically, a Windows reboot is required. This can be done while the control system is running as the PLC control functionality is not affected.

As a general security measure, Siemens strongly recommends users protect network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends users configure the environment according to Siemens’ operational guidelines for industrial security and follow the recommendations in the product manuals.

For more information, please see Siemens Security Advisory SSA-700697

Plugin Details

Severity: High

ID: 500454

Version: 1.8

Type: remote

Family: Tenable.ot

Published: 2/7/2022

Updated: 3/4/2024

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 3.6

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-2020-15796

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:N/A:H

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

Vulnerability Information

CPE: cpe:/o:siemens:simatic_et_200sp_open_controller_firmware, cpe:/o:siemens:simatic_s7-1500_software_controller_firmware

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 12/14/2020

Vulnerability Publication Date: 12/14/2020

Reference Information

CVE: CVE-2020-15796

CWE: 248

Detections

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