Siemens LOGO! CMR and SIMATIC RTU 3000 Use of Insufficiently Random Values (CVE-2021-37186)

medium Tenable OT Security Plugin ID 501666

Synopsis

The remote OT asset is affected by a vulnerability.

Description

A vulnerability has been identified in LOGO! CMR2020 (All versions < V2.2), LOGO! CMR2040 (All versions < V2.2), SIMATIC RTU3010C (All versions < V4.0.9), SIMATIC RTU3030C (All versions < V4.0.9), SIMATIC RTU3031C (All versions < V4.0.9), SIMATIC RTU3041C (All versions < V4.0.9). The underlying TCP/IP stack does not properly calculate the random numbers used as ISN (Initial Sequence Numbers). An adjacent attacker with network access to the LAN interface could interfere with traffic, spoof the connection and gain access to sensitive information.

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 identified the following specific workarounds and mitigations users can apply to reduce the risk:

- LOGO! CMR2020 and CMR2040: Update to v2.2 or later version

- SIMATIC RTU 3000 family: Update to v4.0.9 or later version

As a general security measure, Siemens strongly recommends protecting network access to devices with appropriate mechanisms. In order 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.

Additional information on industrial security by Siemens can be found at: https://www.siemens.com/industrialsecurity

For more information about this issue, please see Siemens Security Advisory SSA-316383

Plugin Details

Severity: Medium

ID: 501666

Version: 1.5

Type: remote

Family: Tenable.ot

Published: 9/21/2023

Updated: 9/4/2024

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 2.5

CVSS v2

Risk Factor: Medium

Base Score: 4.8

Temporal Score: 3.5

Vector: CVSS2#AV:A/AC:L/Au:N/C:P/I:P/A:N

CVSS Score Source: CVE-2021-37186

CVSS v3

Risk Factor: Medium

Base Score: 5.4

Temporal Score: 4.7

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

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

Vulnerability Information

CPE: cpe:/o:siemens:logo%21_cmr2020_firmware, cpe:/o:siemens:logo%21_cmr2040_firmware

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 9/14/2021

Vulnerability Publication Date: 9/14/2021

Reference Information

CVE: CVE-2021-37186

CWE: 330

ICSA: 21-257-13

Detections

Analytics