Overview
CVE-2025-59697 describes a security vulnerability affecting Entrust nShield Connect XC, nShield 5c, and nShield HSMi devices through version 13.6.11, and 13.7. This vulnerability, identified as F06, allows a physically proximate attacker to escalate privileges. The attacker can achieve this by editing the Legacy GRUB bootloader configuration to initiate a root shell upon booting the host operating system.
Technical Details
The vulnerability stems from insufficient protection of the Legacy GRUB bootloader configuration on the affected Entrust nShield HSMs. A physically proximate attacker with access to the HSM’s console can modify the GRUB configuration to add parameters that initiate a root shell during the boot process. This grants the attacker full administrative privileges on the underlying host OS, bypassing normal security measures.
The specific attack vector involves altering the grub.cfg file or other related configuration files to include boot parameters such as init=/bin/bash or similar commands that directly launch a shell as root during system initialization. Because these changes occur at the boot level, they circumvent standard authentication and authorization mechanisms.
CVSS Analysis
Currently, a CVSS score has not been assigned to CVE-2025-59697 (N/A). However, given that the vulnerability allows for complete privilege escalation and requires only physical proximity, it is likely to receive a high CVSS score upon evaluation. The lack of a current score does not diminish the criticality of addressing this issue.
A future CVSS score would be expected to consider the following factors:
- Attack Vector (AV): Physical (P) – due to the physical proximity requirement.
- Attack Complexity (AC): Low (L) – due to the relatively straightforward modification of the GRUB configuration.
- Privileges Required (PR): None (N) – No prior privileges are required to access the device physically.
- User Interaction (UI): None (N) – No user interaction is required to exploit the vulnerability.
- Scope (S): Changed (C) – The vulnerability affects the entire system.
- Confidentiality Impact (C): High (H) – Complete compromise of confidentiality.
- Integrity Impact (I): High (H) – Complete compromise of integrity.
- Availability Impact (A): High (H) – Complete compromise of availability.
Possible Impact
The successful exploitation of CVE-2025-59697 can have severe consequences:
- Complete System Compromise: The attacker gains full root access to the host operating system.
- Data Breach: Sensitive data stored within the HSM or accessible to the host OS can be stolen.
- Key Extraction: Cryptographic keys stored within the HSM could potentially be extracted, compromising the security of applications and systems relying on those keys.
- Malware Installation: The attacker can install persistent malware on the host OS.
- Service Disruption: The attacker can disrupt or completely disable services relying on the HSM.
Given the critical role of HSMs in securing sensitive data and operations, this vulnerability represents a significant risk to organizations using affected Entrust nShield devices.
Mitigation or Patch Steps
Entrust has been notified of this vulnerability and is expected to release a patch or mitigation guidance. In the meantime, consider the following interim measures:
- Physical Security: Ensure stringent physical security controls are in place to prevent unauthorized access to the HSM console. Limit physical access to authorized personnel only.
- Boot Security: Investigate options to secure the boot process, such as enabling Secure Boot or using signed bootloaders, if supported by the hardware and operating system. This may require careful configuration and testing to ensure compatibility with the HSM software.
- Monitoring: Implement monitoring solutions to detect unauthorized changes to the GRUB configuration files.
- Stay Informed: Monitor Entrust’s security advisories for official patches and mitigation instructions. Entrust’s Website is the best source for official guidance.
Important: Applying mitigation steps or waiting for a patch should be done according to the security policies of your organization.
