CVE-2025-40938
Published: 09 December 2025
Summary
CVE-2025-40938 is a critical-severity Use of Hard-coded Credentials (CWE-798) vulnerability in Siemens Simatic Cn 4100 Firmware. Its CVSS base score is 9.2 (Critical).
Operationally, ranked at the 15.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-201918
Vulnerability details
A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected device stores sensitive information in the firmware. This could allow an attacker to access and misuse this information, potentially impacting the device’s confidentiality, integrity, and…
more
availability.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Enables users to notice when hard-coded credentials have been exploited for unauthorized access.
Security training explicitly warns against hard-coded credentials, lowering their use in systems.
Policy and procedures prohibit hard-coded credentials in favor of managed authentication.
External identity providers eliminate the need for hard-coded credentials in applications.
Changing default authenticators prior to first use and protecting content prevents use of hard-coded credentials.
Central credential stores and rotation policies remove the need for hard-coded credentials in configuration files or code.
Intelligence programs surface reports of campaigns that abuse hard-coded credentials in products, prompting removal or replacement and thereby reducing successful exploitation.
Planned investment enables secure credential storage and management systems instead of hard-coded credentials.