Siemens SIPROTEC 5

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, see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global).

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1. EXECUTIVE SUMMARY

• CVSS v4 6.0
• ATTENTION: Exploitable remotely
• Vendor: Siemens
• Equipment: SIPROTEC 5
• Vulnerability: Use of GET Request Method With Sensitive Query Strings

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an attacker to retrieve sensitive session data from browser history, logs, or other storage mechanisms, potentially leading to unauthorized access.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Siemens reports that the following products are affected:

• SIPROTEC 5 6MD84 (CP300): All versions
• SIPROTEC 5 7SA86 (CP300): All versions
• SIPROTEC 5 7SA87 (CP300): All versions
• SIPROTEC 5 7SD82 (CP100): All versions
• SIPROTEC 5 7SD82 (CP150): All versions
• SIPROTEC 5 7SD86 (CP300): All versions
• SIPROTEC 5 7SD87 (CP300): All versions
• SIPROTEC 5 7SJ81 (CP100): All versions
• SIPROTEC 5 7SJ81 (CP150): All versions
• SIPROTEC 5 7SJ82 (CP100): All versions
• SIPROTEC 5 7SJ82 (CP150): All versions
• SIPROTEC 5 6MD85 (CP300): All versions
• SIPROTEC 5 7SJ85 (CP300): All versions
• SIPROTEC 5 7SJ86 (CP300): All versions
• SIPROTEC 5 7SK82 (CP100): All versions
• SIPROTEC 5 7SK82 (CP150): All versions
• SIPROTEC 5 7SK85 (CP300): All versions
• SIPROTEC 5 7SL82 (CP100): All versions
• SIPROTEC 5 7SL82 (CP150): All versions
• SIPROTEC 5 7SL86 (CP300): All versions
• SIPROTEC 5 7SL87 (CP300): All versions
• SIPROTEC 5 7SS85 (CP300): All versions
• SIPROTEC 5 6MD86 (CP300): All versions
• SIPROTEC 5 7ST85 (CP300): All versions
• SIPROTEC 5 7ST86 (CP300): All versions
• SIPROTEC 5 7SX82 (CP150): All versions
• SIPROTEC 5 7SX85 (CP300): All versions
• SIPROTEC 5 7SY82 (CP150): All versions
• SIPROTEC 5 7UM85 (CP300): All versions
• SIPROTEC 5 7UT82 (CP100): All versions
• SIPROTEC 5 7UT82 (CP150): All versions
• SIPROTEC 5 7UT85 (CP300): All versions
• SIPROTEC 5 7UT86 (CP300): All versions
• SIPROTEC 5 6MD89 (CP300): All versions
• SIPROTEC 5 7UT87 (CP300): All versions
• SIPROTEC 5 7VE85 (CP300): All versions
• SIPROTEC 5 7VK87 (CP300): All versions
• SIPROTEC 5 7VU85 (CP300): All versions
• SIPROTEC 5 Compact 7SX800 (CP050): All versions
• SIPROTEC 5 6MD89 (CP300) V9.6: All versions
• SIPROTEC 5 6MU85 (CP300): All versions
• SIPROTEC 5 7KE85 (CP300): All versions
• SIPROTEC 5 7SA82 (CP100): All versions
• SIPROTEC 5 7SA82 (CP150): All versions

3.2 VULNERABILITY OVERVIEW

3.2.1 USE OF GET REQUEST METHOD WITH SENSITIVE QUERY STRINGS CWE-598

The affected devices include session identifiers in URL requests for certain functionalities. This could allow an attacker to retrieve sensitive session data from browser history, logs, or other storage mechanisms, potentially leading to unauthorized access.

CVE-2025-40742 has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N).

A CVSS v4 score has also been calculated for CVE-2025-40742. A base score of 6.0 has been calculated; the CVSS vector string is (CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N).

3.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Energy, Critical Manufacturing
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: Siemens

3.4 RESEARCHER

Nozomi Networks reported this vulnerability to Siemens.

4. MITIGATIONS

Siemens is preparing fixed versions and recommends countermeasures for products where fixes are unavailable or not yet available.

Operators of critical power systems (e.g., TSOs or DSOs) worldwide are typically required by regulations to build resilience into the power grids by applying multi-level redundant secondary protection schemes. Therefore, operators should check whether appropriate resilient protection measures are in place. The risk of cyber incidents affecting the grid's reliability can thus be minimized by the grid design. Siemens strongly recommends applying the provided security updates using the corresponding tools and documented procedures that accompany the product. If the product supports this capability, an automated method can be used to apply the security updates across multiple product instances. Siemens strongly recommends validating any security update before it is applied and ensuring that trained staff supervise the update process in the target environment. As a general security measure, Siemens strongly recommends protecting network access with appropriate security mechanisms (e.g., firewalls, segmentation, VPN). It is advised that the environment be configured according to Siemens' operational guidelines to operate the devices in a protected IT environment.

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-904646 in HTML and CSAF.

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. 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:

• Do not click web links or open attachments in unsolicited email messages.
• Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
• Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.

No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time. This vulnerability has a high attack complexity.

5. UPDATE HISTORY

• July 10, 2025: Initial Republication of Siemens SSA-904646

• Siemens