Overview
A critical physical security vulnerability, identified as CVE-2025-59703, has been discovered in Entrust nShield Connect XC, nShield 5c, and nShield HSMi devices. This flaw allows a physically proximate attacker to gain access to the internal components of the Hardware Security Module (HSM) without triggering tamper evidence mechanisms. This attack, known as an F14 attack, exploits the device’s physical design and the ease with which the tamper labels and fixing screws can be removed without causing obvious damage.
Technical Details
The vulnerability stems from the design of the nShield HSM casing and the tamper-evident mechanisms employed. An attacker with physical access can carefully remove the tamper label and all fixing screws securing the device’s enclosure. The precision required for this attack highlights the need for enhanced physical security controls. The vulnerability affects Entrust nShield Connect XC, nShield 5c, and nShield HSMi devices running firmware versions up to and including 13.6.11, as well as version 13.7.
CVSS Analysis
Currently, a CVSS score has not been assigned to CVE-2025-59703. This is likely due to the nature of physical vulnerabilities, which are often difficult to quantify using standard CVSS metrics. The severity is also listed as N/A. However, the potential impact of a successful exploit should be considered high, as it allows an attacker to compromise the HSM’s cryptographic secrets.
Possible Impact
A successful F14 attack against an Entrust nShield HSM can have severe consequences, including:
- Key Extraction: The attacker could potentially extract cryptographic keys stored within the HSM.
- Data Compromise: With access to the HSM’s keys, sensitive data encrypted using those keys could be decrypted and compromised.
- System Impersonation: The attacker could use the compromised HSM to impersonate legitimate systems or users, leading to unauthorized access and malicious activities.
- Reputational Damage: A security breach involving an HSM can severely damage an organization’s reputation and erode customer trust.
Mitigation or Patch Steps
Unfortunately, no specific patch addresses the underlying design flaw that enables the F14 attack directly. Mitigation strategies must focus on enhancing physical security controls:
- Enhanced Physical Security: Implement stricter physical access controls to the HSMs, including surveillance, access logs, and environmental monitoring.
- Tamper-Resistant Enclosures: Consider using additional tamper-resistant enclosures or security cages to further protect the HSMs.
- Regular Inspections: Conduct regular physical inspections of the HSMs to check for any signs of tampering.
- Environmental Monitoring: Monitor the HSM environment for unusual activity or disturbances that might indicate an attempted breach.
- Proactive Monitoring: Implement logging and monitoring that will alert administrators of any changes in the HSM’s state or configuration.
