CVE-2026-42951: MacGregor VDR G4E Backup Credential Disclosure – Patch Guidance

Technical summary

CVE-2026-42951 is an improper credential storage vulnerability (CWE-522) affecting MacGregor Interschalt VDR G4E devices and firmware. The backup download functionality does not properly segregate or redact sensitive authentication material, allowing an authenticated user with legitimate system access to retrieve account data and password hashes via a backup export operation. The CVSS 3.1 score of 5.4 (MEDIUM) reflects the authentication prerequisite, high confidentiality impact, and limited integrity exposure. The attack vector is adjacent network, suggesting attackers must be on the same network segment or have network-adjacent access.

Business impact

VDR devices are critical infrastructure on modern vessels, recording bridge operations and voyage data for regulatory compliance and incident investigation. Compromise of account credentials could allow malicious insiders or network-adjacent attackers to assume administrative roles, manipulate voyage records, disable logging, or facilitate further lateral movement to other maritime IT systems. For operators, loss of VDR integrity compromises both regulatory defensibility and situational awareness. The exposure of password hashes elevates risk if credentials are reused across vessel or shore-based systems.

Affected systems

MacGregor Interschalt VDR G4E (and G4E firmware versions) are affected. Verify your specific firmware version against the vendor advisory to confirm patch eligibility. If your organization operates multiple VDR installations or integrated bridge systems from MacGregor, inventory all G4E instances immediately.

Exploitability

Exploitation requires valid authenticated access to the VDR device. An attacker cannot exploit this remotely without first obtaining legitimate credentials. However, the barrier to exploit is moderate: once insider access or credential compromise occurs, the backup download is a standard administrative function that an attacker can invoke without additional detection evasion. The exposed password hashes may be cracked offline to obtain cleartext passwords, extending the window of exposure.

Remediation

Apply the vendor-supplied patch to affected Interschalt VDR G4E devices and firmware as outlined in the MacGregor advisory. Restrict backup download privileges to essential personnel and enforce role-based access controls (RBAC). Review and rotate any credentials exposed via backups already downloaded by unauthorized users. Implement network segmentation to limit authenticated access to VDR administrative functions. Consider implementing additional controls such as backup encryption and signed integrity verification.

Patch guidance

Consult the MacGregor security advisory for the specific patched firmware version and deployment procedure for your G4E model. Patches are typically delivered via firmware updates; coordinate with your vessel IT operations or shore-based support to stage and validate updates in a non-disruptive manner. Verify patch application by confirming firmware version post-deployment and testing backup functionality to ensure integrity is maintained.

Detection guidance

Monitor VDR backup download operations, particularly those initiated by non-administrative accounts or during unusual hours. Log all backup exports and archive metadata (timestamp, user, destination). Detect anomalous patterns such as repeated failed backup attempts, downloads to external storage, or access from unexpected network origins. Review VDR audit logs regularly for any unauthorized administrative activities. Implement alerting on authentication anomalies (failed logins, privilege escalation attempts) targeting VDR systems.

Why prioritize this

Although classified as MEDIUM severity, this vulnerability warrants prompt remediation because: (1) VDR systems operate in safety-critical maritime environments where data integrity is regulatory and operational priority; (2) password hash exposure creates a secondary risk of credential reuse on ship and shore systems; (3) authenticated insiders pose a credible threat in the maritime sector; (4) remediation is straightforward via patching. Organizations with VDR systems should treat this as a near-term priority, particularly if their credential hygiene or network segmentation is weak.

Risk score, explained

The CVSS 3.1 score of 5.4 reflects a medium-severity issue: high confidentiality impact (password hash disclosure) balanced against the requirement for authenticated access (PR:L) and adjacent network positioning (AV:A). The score does not capture the regulatory or operational significance of VDR compromise, which may warrant higher-priority treatment in a maritime risk context.

Frequently asked questions