As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens’ ProductCERT Security Advisories (CERT Services | Services | Siemens Global).
1. EXECUTIVE SUMMARY
- CVSS v3 4.3
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Siemens
- Equipment: SINEMA Remote Connect Server
- Vulnerabilities: Incorrect Permission Assignment for Critical Resource, Incorrect Authorization
2. RISK EVALUATION
Successful exploitation of these vulnerabilities could allow an authenticated attacker to impersonate the server potentially enabling man-in-the-middle, traffic decryption, or unauthorized access to services that trust these certificates.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
Siemens reports that the following products are affected:
- SINEMA Remote Connect Server: All versions prior to V3.2 SP4
3.2 VULNERABILITY OVERVIEW
3.2.1 INCORRECT PERMISSION ASSIGNMENT FOR CRITICAL RESOURCE CWE-732
Affected applications contain private SSL/TLS keys on the server that are not properly protected allowing any user with server access to read these keys. This could allow an authenticated attacker to impersonate the server potentially enabling man-in-the-middle, traffic decryption or unauthorized access to services that trust these certificates.
CVE-2025-40818 has been assigned to this vulnerability. A CVSS v3.1 base score of 3.3 has been calculated; the CVSS vector string is (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).
3.2.2 INCORRECT AUTHORIZATION CWE-863
Affected applications do not properly validate license restrictions against the database, allowing direct modification of the system_ticketinfo table to bypass license limitations without proper enforcement checks. This could allow an attacker with database access to circumvent licensing restrictions by directly modifying database values and potentially enabling unauthorized use beyond the permitted scope.
CVE-2025-40819 has been assigned to this vulnerability. A CVSS v3.1 base score of 4.3 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N).
3.3 BACKGROUND
- CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing
- COUNTRIES/AREAS DEPLOYED: Worldwide
- COMPANY HEADQUARTERS LOCATION: Germany
3.4 RESEARCHER
Siemens ProductCERT reported these vulnerabilities to CISA.
4. MITIGATIONS
Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk:
- SINEMA Remote Connect Server: Update to V3.2 SP4 or later version
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-626856 in HTML and CSAF.
CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities, such as:
- Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet.
- Locate control system networks and remote devices behind firewalls and isolating them from business networks.
- When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs). Recognize VPNs may have vulnerabilities, should be updated to the most recent version available, and are only as secure as the connected devices.
CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.
Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov in the technical information paper, ICS-TIP-12-146-01B–Targeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.
CISA also recommends users take the following measures to protect themselves from social engineering attacks:
No known public exploitation specifically targeting these vulnerabilities has been reported to CISA at this time.
5. UPDATE HISTORY
- December 11, 2025: Initial Republication of Siemens ProductCERT SSA-626856