Siemens SIMATIC S7-400 Improper Restriction of Operations Within the Bounds of a Memory Buffer (CVE-2021-40368)

high Tenable OT Security Plugin ID 500632

Synopsis

The remote OT asset is affected by a vulnerability.

Description

A vulnerability has been identified in SIMATIC S7-400 H V6 CPU family (incl. SIPLUS variants) (All versions < V6.0.10), SIMATIC S7-400 PN/DP V7 CPU family (incl. SIPLUS variants) (All versions), SIMATIC S7-410 V10 CPU family (incl. SIPLUS variants) (All versions < V10.1), SIMATIC S7-410 V8 CPU family (incl. SIPLUS variants) (All versions). Affected devices improperly handle specially crafted packets sent to port 102/tcp. This could allow an attacker to create a Denial-of-Service condition. A restart is needed to restore normal operations.

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 their software to the most current version where available:

- SIMATIC S7-400 HV6 CPU family (incl. SIPLUS variants): Update to v6.0.10 or later
- SIMATIC S7-400 PN/DP V7 CPU family (incl. SIPLUS variants): No current fix is available

- SIMATIC S7-410 V8 CPU family (incl. SIPLUS variants): Update to v8.2.3 or later

- SIMATIC S7-410 V10 CPU family (incl. SIPLUS variants): Update to v10.1 or later

- To obtain SIMATIC S7-410 v10.1 contact Siemens support

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

- Limit access to Port 102/TCP to trusted users and systems only

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 the Siemens operational guidelines for industrial security and following the recommendations in the product manuals.

For additional information, please refer to Siemens Security Advisory SSA-557541

Plugin Details

Severity: High

ID: 500632

Version: 1.7

Type: remote

Family: Tenable.ot

Published: 4/28/2022

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-2021-40368

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_s7-400h_v6_firmware, cpe:/o:siemens:simatic_s7-400_pn%2fdp_v7_firmware

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 4/12/2022

Vulnerability Publication Date: 4/12/2022

Reference Information

CVE: CVE-2021-40368

CWE: 119

Detections

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