SSA-390352

Siemens Security Advisory by Siemens ProductCERT

SSA-390352: Multiple Vulnerabilities in .NET Client Library for SIMATIC S7 Webserver API

Publication Date:	2026-10-13
Last Update:	2026-10-13
Current Version:	V1.0
CVSS v3.1 Base Score:	7.5
CVSS v4.0 Base Score:	8.7

SUMMARY

.NET Client Library for SIMATIC S7 Webserver API contains multiple vulnerabilities that could allow an attacker to obtain sensitive information or write arbitrary files outside the intended download directory.

Siemens has released a new version for .NET Client Library for SIMATIC S7 Webserver API and recommends to update to the latest version.

KNOWN AFFECTED PRODUCTS

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Affected Product and Versions	Remediation
.NET Client Library for SIMATIC S7 Webserver API	Show more details
.NET Client Library for SIMATIC S7 Webserver API All versions < V3.3.61 affected by CVE-2026-85114	Update to V3.3.61 or later version https://github.com/siemens/simatic-s7-webserver-api/releases/tag/v3.3.61
.NET Client Library for SIMATIC S7 Webserver API All versions < V3.3.62 affected by CVE-2026-85115	Update to V3.3.62 or later version https://github.com/siemens/simatic-s7-webserver-api/releases/tag/v3.3.62

MITIGATIONS

Product-specific remediations or mitigations can be found in the section Known Affected Products.
Please follow the General Security Recommendations.

GENERAL SECURITY RECOMMENDATIONS

As a general security measure, Siemens strongly recommends to protect 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 (Download: https://www.siemens.com/cert/operational-guidelines-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

VULNERABILITY DESCRIPTION

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This chapter describes all vulnerabilities (CVE-IDs) addressed in this security advisory. Wherever applicable, it also documents the product-specific impact of the individual vulnerabilities.

Vulnerability CVE-2026-85114

Affected applications do not properly validate filenames received from remote servers during ticket downloads.

This could allow an attacker who can manipulate the ticket response to write arbitrary files outside the intended download directory and, when overwriting is enabled, replace existing files accessible to the application.

CVSS v3.1 Base Score	7.5
CVSS v3.1 Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS v4.0 Base Score	8.7
CVSS v4.0 Vector	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
CWE	CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Vulnerability CVE-2026-85115

Affected applications do not properly redact PLC restore passwords from HTTP error exception messages.

This could allow an attacker with access to logs or other diagnostic output to obtain the plaintext restore password and potentially perform unauthorized operations on the PLC.

CVSS v3.1 Base Score	5.5
CVSS v3.1 Vector	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS v4.0 Base Score	6.8
CVSS v4.0 Vector	CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CWE	CWE-209: Generation of Error Message Containing Sensitive Information

ADDITIONAL INFORMATION

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

HISTORY DATA

V1.0 (2026-10-13):

Publication Date

The use of Siemens Security Advisories is subject to the terms and conditions listed on: https://www.siemens.com/productcert/terms-of-use.