CVE-2025-40805
Unknown Unknown - Not Provided
Authentication Bypass in Siemens API Enables Remote User Impersonation

Publication date: 2026-01-13

Last updated on: 2026-01-13

Assigner: Siemens AG

Description
Affected devices do not properly enforce user authentication on specific API endpoints. This could facilitate an unauthenticated remote attacker to circumvent authentication and impersonate a legitimate user. Successful exploitation requires that the attacker has learned the identity of a legitimate user.
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Meta Information
Published
2026-01-13
Last Modified
2026-01-13
Generated
2026-06-16
AI Q&A
2026-01-13
EPSS Evaluated
2026-06-15
NVD
CVE-2025-40805
EUVD
EUVD-2026-2362
Affected Vendors & Products
Showing 5 associated CPEs
Vendor Product Version / Range
siemens industrial_edge_device_kit From 1.5 (inc) to 1.23 (inc)
siemens simatic_hmi_unified_comfort_panels to 21 (exc)
siemens simatic_automation_workstations *
siemens simatic_hmi_unified_comfort_panels 21
siemens simatic_hmi_unified_comfort_panels 21.0
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-639 The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
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Executive Summary

This vulnerability is a critical authorization bypass in Siemens Industrial Edge Devices and SIMATIC HMI Unified Comfort Panels. It occurs because affected devices do not properly enforce user authentication on specific API endpoints. This flaw allows an unauthenticated remote attacker, who knows the identity of a legitimate user, to bypass authentication and impersonate that user, gaining unauthorized access to the system. [1, 2]

Impact Analysis

The vulnerability can have severe impacts including unauthorized remote access to affected devices, allowing attackers to impersonate legitimate users. This can lead to full compromise of confidentiality, integrity, and availability of the system, potentially disrupting industrial operations and exposing sensitive data. The vulnerability has a maximum severity score of 10.0, indicating critical risk. [1, 2]

Mitigation Strategies

To mitigate CVE-2025-40805, immediately restrict network access to affected Siemens devices to trusted parties only. Apply available updates: update Industrial Edge Device Kit to version V1.24.2 or later (arm64 and x86-64) and SIMATIC HMI Unified Comfort Panels to version V21 or later. For devices without available fixes, apply interim countermeasures as detailed in Siemens advisories and follow Siemens' operational guidelines for Industrial Security. Refer to Siemens' official support link for detailed mitigation instructions. [1, 2]

Compliance Impact

The provided resources do not explicitly discuss the impact of this vulnerability on compliance with common standards and regulations such as GDPR or HIPAA. However, given that the vulnerability allows unauthenticated remote attackers to bypass authentication and impersonate legitimate users, it could potentially lead to unauthorized access to sensitive data, which may result in non-compliance with data protection regulations that require strict access controls and user authentication. Siemens recommends restricting network access to trusted parties and following security best practices to mitigate risks, which aligns with compliance requirements. Nonetheless, no direct statements about compliance impact are provided. [1, 2]

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