Siemens Desigo PXC and DXR Devices Uncaught Exception (CVE-2021-41545)

high Tenable OT Security Plugin ID 500787

Synopsis

The remote OT asset is affected by a vulnerability.

Description

A vulnerability has been identified in Desigo DXR2 (All versions < V01.21.142.5-22), Desigo PXC3 (All versions < V01.21.142.4-18), Desigo PXC4 (All versions < V02.20.142.10-10884), Desigo PXC5 (All versions < V02.20.142.10-10884). When the controller receives a specific BACnet protocol packet, an exception causes the BACnet communication function to go into a out of work state and could result in the controller going into a factory reset state.

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 recommends updating to the latest software version:

- Desigo DXR2: Update to v01.21.142.5-22 or later
- Desigo PXC3: Update to v01.21.142.4-18 or later
- Desigo PXC4: Update to v02.20.142.10-10884 or later
- Desigo PXC5: Update to v02.20.142.10-10884 or later

Contact Siemens for update information.

As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens’ operational guidelines for industrial security and following the recommendations in the product manuals.

For additional information, please refer to Siemens Security Advisory SSA-626968

For additional information, please refer to Siemens Security Advisory SSA-662649

Plugin Details

Severity: High

ID: 500787

Version: 1.4

Type: remote

Family: Tenable.ot

Published: 1/25/2023

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-2021-41545

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:desigo_dxr2_firmware, cpe:/o:siemens:desigo_pxc3_firmware, cpe:/o:siemens:desigo_pxc4_firmware, cpe:/o:siemens:desigo_pxc5_firmware

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 5/10/2022

Vulnerability Publication Date: 5/10/2022

Reference Information

CVE: CVE-2021-41545

Detections

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