Siemens LOGO! 8 BM Use of Hard-Coded Cryptographic Key (CVE-2020-25229)

high Tenable OT Security Plugin ID 501670


The remote OT asset is affected by a vulnerability.


A vulnerability has been identified in LOGO! 8 BM (incl. SIPLUS variants) (All versions < V8.3). The implemented encryption for communication with affected devices is prone to replay attacks due to the usage of a static key. An attacker could change the password or change the configuration on any affected device if using prepared messages that were generated for another device.

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

Siemens has released updates for the affected products and recommends users update to the latest versions:

- LOGO! 8 BM (incl. SIPLUS variants): Update to v8.3; A new hardware version is required in order to update
- LOGO! Soft Comfort: Update to v8.3

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

- Protect access to Port 10005/TCP
- Apply defense-in-depth concept, including protection concept outlined in the system manual.

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 to follow the recommendations in the product manuals.

Additional information on Industrial Security by Siemens can be found at:

For more information, please see Siemens Security Advisory SSA-480824

See Also

Plugin Details

Severity: High

ID: 501670

Version: 1.4

Type: remote

Family: Tenable.ot

Published: 9/21/2023

Updated: 3/4/2024

Supported Sensors: Tenable OT Security

Risk Information


Risk Factor: Low

Score: 3.6


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-2020-25229


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:logo%21_8_bm_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-2020-25229

CWE: 798