Overview
CVE-2025-59694 is a security vulnerability affecting the Chassis Management Board in Entrust nShield Connect XC, nShield 5c, and nShield HSMi devices. This vulnerability, dubbed F03 by some researchers, allows a physically proximate attacker to persistently modify firmware and influence the appliance’s boot process. Successful exploitation requires physical access to the device and the ability to modify firmware either via JTAG or by performing a malicious upgrade to the chassis management board firmware.
Technical Details
The vulnerability stems from an insecure configuration within the Chassis Management Board’s boot process. An attacker with physical access can leverage JTAG debugging interfaces or a carefully crafted firmware upgrade to inject malicious code into the board’s firmware. This allows them to gain control over the boot process and potentially compromise the entire Hardware Security Module (HSM). This exploit modifies the underlying firmware. The vulnerability affects Entrust nShield Connect XC, nShield 5c, and nShield HSMi devices through versions 13.6.11 and 13.7.
CVSS Analysis
Currently, a CVSS score has not been assigned to CVE-2025-59694. However, given that it requires physical access and the potential impact on the HSM’s security, the severity should be considered high. A successful exploit could lead to complete compromise of the HSM and the sensitive data it protects.
Possible Impact
The successful exploitation of CVE-2025-59694 can have severe consequences:
- Data Breach: Compromised HSMs can expose sensitive cryptographic keys and data, leading to a data breach.
- Loss of Trust: Compromise of the HSM undermines the trust in the cryptographic operations performed by the device.
- Service Disruption: Attackers can disrupt services that rely on the HSM by rendering the device unusable or manipulating its functionality.
- Supply Chain Attacks: A compromised HSM can be used as a stepping stone for further attacks within the organization.
Mitigation or Patch Steps
Entrust has not yet released a specific patch or mitigation advisory for CVE-2025-59694 as of the current update of this article. However, the following steps can be taken to mitigate the risk:
- Physical Security: Implement strong physical security measures to prevent unauthorized access to the HSMs. This includes secure data centers, access controls, and monitoring.
- Firmware Updates: Regularly monitor Entrust’s website for security advisories and firmware updates. Apply updates as soon as they are available.
- JTAG Security: Disable or restrict access to the JTAG debugging interface to prevent unauthorized firmware modification. If JTAG is needed for troubleshooting, enable and disable it securely.
- Intrusion Detection: Implement intrusion detection systems to monitor for suspicious activity around the HSMs.
