Siemens SIMATIC S7-1500 Cleartext Transmission of Sensitive Information (CVE-2021-22946)

high Tenable OT Security Plugin ID 504144

Synopsis

The remote OT asset is affected by a vulnerability.

Description

A user can tell curl >= 7.20.0 and <= 7.78.0 to require a successful upgrade to TLS when speaking to an IMAP, POP3 or FTP server (--ssl- reqd on the command line orCURLOPT_USE_SSL set to CURLUSESSL_CONTROL or CURLUSESSL_ALL withlibcurl). This requirement could be bypassed if the server would return a properly crafted but perfectly legitimate response.This flaw would then make curl silently continue its operations WITHOUTTLS contrary to the instructions and expectations, exposing possibly sensitive data in clear text over the network.

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 users update the product to the following versions:

- Update to V2.16.0 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 to 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:
https://www.siemens.com/industrialsecurity

For further inquiries on security vulnerabilities in Siemens products and solutions, please contact the Siemens ProductCERT: https://www.siemens.com/cert/advisories

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 recommendations in the product manuals.

Additional information on industrial security by Siemens can be found on the Siemens industrial security webpage.

For more information see the associated Siemens security advisory SSA-146325 in HTML and CSAF.

Plugin Details

Severity: High

ID: 504144

File Name: tenable_ot_siemens_CVE-2021-22946.nasl

Version: 1.3

Type: remote

Family: Tenable.ot

Published: 11/13/2025

Updated: 3/5/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.7

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

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

Vulnerability Information

CPE: cpe:/o:siemens:ruggedcom_rox_rx1400_firmware, cpe:/o:siemens:ruggedcom_rox_rx1500_firmware, cpe:/o:siemens:ruggedcom_rox_rx1512_firmware, cpe:/o:siemens:ruggedcom_rox_rx1501_firmware, cpe:/o:siemens:simatic_s7-1500_cpu_firmware:3.1.5, cpe:/o:siemens:ruggedcom_rox_rx1536_firmware, cpe:/o:siemens:ruggedcom_rox_rx1524_firmware, cpe:/o:siemens:ruggedcom_rox_rx1511_firmware, cpe:/o:siemens:ruggedcom_rox_rx5000_firmware, cpe:/o:siemens:ruggedcom_rox_mx5000_firmware, cpe:/o:siemens:ruggedcom_rox_mx5000re_firmware, cpe:/o:siemens:siplus_s7-1500_cpu_firmware:3.1.5, cpe:/o:siemens:ruggedcom_rox_rx1510_firmware

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 3/8/2022

Vulnerability Publication Date: 3/8/2022

Reference Information

CVE: CVE-2021-22946

CWE: 319

ICSA: 23-194-01

Detections

Analytics