Cyber Resilience

CVE-2025-59694

Entrust Nshield 5C Firmware ≤ 13.6.12

Public PoC
Published
02 December 2025
Modified
15 December 2025
Patch / advisory
CVSS Score v3.1 6.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0027 19th percentile
Risk Priority 45 floored blend · peak EPSS

Summary

CVE-2025-59694 is a medium-severity Improper Access Control for Volatile Memory Containing Boot Code (CWE-1274) vulnerability in Entrust Nshield 5C Firmware. Its CVSS base score is 6.8 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Component Firmware (T1542.002); ranked at the 19th 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 map to PE-3 (Physical Access Control) and SA-18 (Tamper Resistance and Detection) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

The Chassis Management Board in Entrust nShield Connect XC, nShield 5c, and nShield HSMi through 13.6.11, or 13.7, allows a physically proximate attacker to persistently modify firmware and influence the (insecurely configured) appliance boot process. To exploit this, the attacker…

more

must modify the firmware via JTAG or perform an upgrade to the chassis management board firmware. This is called F03.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1542.002 Component Firmware Stealth
Adversaries may modify component firmware to persist on systems.
T1490 Inhibit System Recovery Impact
Adversaries may delete or remove built-in data and turn off services designed to aid in the recovery of a corrupted system to prevent recovery.
T1685 Disable or Modify Tools Defense Impairment
Adversaries may disable, degrade, or tamper with security tools or applications (e.
T1685.003 Modify or Spoof Tool UI Defense Impairment
Adversaries may spoof or manipulate security tool user interfaces (UIs) to falsely indicate tools are functioning normally and delay detection and response.
Why these techniques?

Vulnerability enables persistent, undetectable firmware modification on chassis management board via JTAG/upgrade, facilitating component firmware alteration for pre-OS boot control/persistence (T1542.002), inhibiting system recovery (T1490), disabling/modifying tamper defenses (T1562.001), and spoofing tamper events/LCD alerts (T1562.011).

CVEs Like This One

CVE-2025-59693Same product: Entrust Nshield 5C
CVE-2025-59703Same product: Entrust Nshield 5C
CVE-2025-59700Same product: Entrust Nshield 5C
CVE-2025-59704Same product: Entrust Nshield 5C
CVE-2025-59695Same product: Entrust Nshield 5C
CVE-2025-59697Same product: Entrust Nshield 5C
CVE-2025-59696Same product: Entrust Nshield 5C
CVE-2025-59698Same product: Entrust Nshield 5C
CVE-2025-59702Same product: Entrust Nshield 5C
CVE-2025-59705Same product: Entrust Nshield 5C

Affected Assets

entrust
nshield 5c firmware
≤ 13.6.12 · 13.7.3 — 13.9.0
entrust
nshield hsmi firmware
≤ 13.6.12 · 13.7.3 — 13.9.0
entrust
nshield connect xc base firmware
≤ 13.6.12 · 13.7.3 — 13.9.0
entrust
nshield connect xc mid firmware
≤ 13.6.12 · 13.7.3 — 13.9.0
entrust
nshield connect xc high firmware
≤ 13.6.12 · 13.7.3 — 13.9.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • PE-3 Physical Access Control
  • SA-18 Tamper Resistance and Detection
  • SI-7 Software, Firmware, and Information Integrity
Detect
Catch it (NIST detect / respond)
  • SA-18 Tamper Resistance and Detection
  • SI-7 Software, Firmware, and Information Integrity
Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly blocks physically proximate attackers from reaching the chassis board to perform JTAG or firmware modifications.

preventdetect

Requires tamper-resistance mechanisms on hardware components to stop unauthorized firmware changes via physical interfaces such as JTAG.

preventdetect

Enforces cryptographic verification of firmware integrity before boot, mitigating the insecure boot-process configuration described in the CVE.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.DS-10 mostly match
prevents

PR.DS-10 directly requires protecting data-in-use (including VM) from unauthorized access, eliminating most of this specific boot-code exposure, yet the weakness also spans secure-boot process design and NVM-to-VM transfer that one general data-protection outcome does not fully close.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.15 Logging partial match
detects

Logging can detect unauthorized writes to volatile memory but does not prevent the weakness.

mitigates

Restricting privileged utilities reduces the chance of tampering with boot code in volatile memory.

prevents

Privileged access rights can limit who or what can write to volatile memory used for boot code.

prevents

Secure system architecture principles include memory protection mechanisms that can mitigate this weakness.

prevents

Information access restriction directly addresses unauthorized access to volatile memory holding boot code.

References