CVE-2025-59695
Published: 02 December 2025
Summary
CVE-2025-59695 is a critical-severity Missing Authentication for Critical Function (CWE-306) vulnerability in Entrust Nshield 5C Firmware. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Clear Linux or Mac System Logs (T1685.006); ranked at the 34.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 AC-6 (Least Privilege) and CM-5 (Access Restrictions for Change).
Deeper analysis
CVE-2025-59695 is a critical vulnerability in Entrust nShield Connect XC, nShield 5c, and nShield HSMi hardware security modules through firmware versions 13.6.11 or 13.7. It enables a user with OS root access to alter firmware on the Chassis Management Board without authentication, an issue tracked as F04 and mapped to CWE-306 (Missing Authentication for Critical Function). The vulnerability carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), highlighting its severity due to network accessibility, low attack complexity, and high impacts across confidentiality, integrity, and availability.
An attacker with root access on the host operating system can exploit this flaw remotely without additional privileges, user interaction, or authentication checks on the Chassis Management Board. Successful exploitation allows arbitrary firmware modification, potentially compromising the HSM's security functions, such as cryptographic key management and attestation.
Advisories are available in the Google security research advisory at https://github.com/google/security-research/security/advisories/GHSA-6q4x-m86j-gfwj and Entrust's HSM documentation at https://www.entrust.com/use-case/why-use-an-hsm. The CVE was published on 2025-12-02T15:15:55.010.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-200259
Vulnerability details
Entrust nShield Connect XC, nShield 5c, and nShield HSMi through 13.6.11, or 13.7, allow a user with OS root access to alter firmware on the Chassis Management Board (without Authentication). This is called F04.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
CVE-2025-59695 and related flaws (F02-F05) enable root users to modify Chassis Management Board firmware without authentication (T1542.002: Component Firmware) and edit unencrypted tamper logs (T1070.002: Clear Linux or Mac System Logs), facilitating undetectable persistence and indicator removal.
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Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Performs integrity verification of firmware on the Chassis Management Board to detect and respond to unauthorized alterations by users with root access.
Enforces least privilege on the host OS to prevent attackers from obtaining root access required to exploit the firmware alteration vulnerability.
Restricts and documents access to changes on HSM components like the Chassis Management Board firmware, mitigating unauthorized modifications even with root privileges.