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

Refer to the vendor advisory.

Plugin Details

Severity: High

ID: 504144

Version: 1.1

Type: remote

Family: Tenable.ot

Published: 11/13/2025

Updated: 11/13/2025

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_rx5000_firmware, cpe:/o:siemens:ruggedcom_rox_rx1501_firmware, cpe:/o:siemens:ruggedcom_rox_rx1500_firmware, cpe:/o:siemens:ruggedcom_rox_rx1512_firmware, cpe:/o:siemens:ruggedcom_rox_mx5000_firmware, cpe:/o:siemens:siplus_s7-1500_cpu_firmware:3.1.5, cpe:/o:siemens:ruggedcom_rox_mx5000re_firmware, cpe:/o:siemens:ruggedcom_rox_rx1536_firmware, cpe:/o:siemens:ruggedcom_rox_rx1524_firmware, cpe:/o:siemens:simatic_s7-1500_cpu_firmware:3.1.5, cpe:/o:siemens:ruggedcom_rox_rx1510_firmware, cpe:/o:siemens:ruggedcom_rox_rx1511_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

Detections

Analytics