Siemens SIMATIC S7-1200 and S7-1500 CPU Families Missing Support For Integrity Check (CVE-2019-10943)

high Tenable OT Security Plugin ID 500055

Synopsis

The remote OT asset is affected by a vulnerability.

Description

An attacker with network access to port 102/tcp could potentially modify the user program on the PLC in a way that the running code is different from the source code which is stored on the device. An attacker must have network access to affected devices and must be able to perform changes to the user program. The vulnerability could impact the perceived integrity of the user program stored on the CPU. An engineer that tries to obtain the code of the user program running on the device, can receive different source code that is not actually running on the device.

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 following products and recommends users update to the new version.

- SIMATIC S7 PLCSIM Advanced: Update to v3.0

- SIMATIC S7-1200 CPU family: Update to v4.4.0

- SIMATIC S7-1500 CPU family: Update to v2.8.1
- SIMATIC S7-1500 Software Controller: Update to v20.8
- SIMATIC ET 200SP Open Controller CPU 1515SP PC2: Update to v20.8

Siemens is preparing further updates and recommends specific countermeasures until patches are available:

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

Plugin Details

Severity: High

ID: 500055

Version: 1.10

Type: remote

Family: Tenable.ot

Published: 2/7/2022

Updated: 9/4/2024

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:P/A:N

CVSS Score Source: CVE-2019-10943

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_firmware, cpe:/o:siemens:simatic_s7-1200_firmware, cpe:/o:siemens:simatic_et_200sp_open_controller_cpu_1515sp_pc2_firmware, cpe:/o:siemens:simatic_et_200sp_open_controller_cpu_1515sp_pc_firmware

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 8/13/2019

Vulnerability Publication Date: 8/13/2019

Reference Information

CVE: CVE-2019-10943

CWE: 345

ICSA: 19-344-06

Detections

Analytics