CVE-2026-44611

Executive Summary

CVE-2026-44611 is a medium-severity cryptographic weakness in the Danelec MacGregor Voyage Data Recorder (VDR) G4e maritime system. The device stores user passwords using a hashing method that both truncates password length and lacks sufficient computational complexity (iterations/work factor), making stored credential hashes trivially susceptible to offline brute-force attacks. An attacker with network access to the device's management interface and valid low-privilege credentials can extract password hashes, crack them offline, and escalate to higher-privileged accounts (e.g., administrator). This affects maritime vessels operating with VDR G4e firmware prior to V5.250, potentially compromising voyage data integrity and vessel operational security.

Technical Analysis

The vulnerability resides in the authentication module of the VDR G4e firmware. The system stores user account passwords using a single-round hashing algorithm (e.g., MD5 or SHA-1 without salt) with an enforced maximum input length of 8 characters. Two flaws compound:

1. Length truncation: Passwords longer than 8 characters are silently truncated before hashing. This dramatically reduces the effective key space. An 8-character alphanumeric password space is ~2.18×10^14 combinations, but with common patterns (e.g., dictionary words plus digits), real-world keyspace is far smaller (practical brute-force range of ~10^9-10^11).
2. Insufficient computational effort: The hash function is executed in a single pass without key stretching (no bcrypt, PBKDF2, scrypt, or Argon2). On modern GPU hardware (e.g., RTX 4090), MD5 achieves ~80 GH/s and SHA-1 ~25 GH/s. Even the full 8-character keyspace can be exhausted in hours; with dictionary attacks, minutes.

Attack surface: The VDR G4e exposes a web-based management interface on ports 80/443 (HTTP/HTTPS). Authenticated users with the lowest privilege level can access a configuration export endpoint that returns user account database entries including password hashes. Alternatively, if an attacker gains filesystem access via a separate vulnerability (e.g., command injection), the hash database resides in /etc/passwd or a proprietary configuration file with world-readable permissions.

Technical mechanism:

• The authentication library checks strlen(password) and truncates to 8 bytes before passing to the hash function.
• The hash is computed as hash = H(truncated_password) (no salt, no pepper, static IV where applicable).
• Stored as plaintext hexadecimal in user_db.xml or equivalent configuration file.
• Login verification re-hashes the input and compares against the stored value.

Exploitation Scenarios

Scenario: Low-privilege to Admin privilege escalation via offline hash cracking

Step 1 — Reconnaissance: Attacker performs a Shodan or Censys search using dorks such as product:"Danelec" port:443 or scans the maritime IP scope (e.g., 192.168.x.x on shipboard networks, or public satellite-connected IPs). They fingerprint the VDR G4e web interface via HTTP response headers (e.g., Server: DanelecWeb/1.4) and the distinctive login page.

Step 2 — Initial Access (low privilege): The attacker uses factory-default credentials or performs a low-effort credential stuffing attack against the login endpoint. Maritime devices often retain default accounts (e.g., user:sailor2024 or op:operator). They authenticate with constrained privileges (read-only access to system status).

Step 3 — Hash Extraction: The attacker navigates to the configuration backup page (/config/export or /admin/download/config.bin), which is accessible to all authenticated users. The file contains the user database including password_hash fields for all accounts (operator, admin, master, service).

Step 4 — Offline Cracking: The attacker extracts hashes and runs hashcat -m 0 -a 3 8d969eef6ecad3c29a3a629280e686cf ?a?a?a?a?a?a?a?a (or mode 100 for SHA-1). Due to the 8-character limit and no salt, the full 8-character printable keyspace is cracked in under 48 hours on a single consumer GPU. In practice, administrator passwords follow maritime conventions (e.g., Master123, VDR2024!), yielding results within minutes using a wordlist combined with rules (hashcat -r best64.rule).

Step 5 — Post-Exploitation: With admin credentials, the attacker:

• Modifies VDR voyage data recording parameters (suppress or alter records).
• Disables alarm triggers in the VDR.
• Extracts full voyage data logs (navigation, communications, sensor data) for espionage or sabotage.
• Installs persistent backdoor via firmware update mechanism (valid but unsigned in legacy firmware).

Known exploitation in the wild: No public PoC or active campaign has been documented as of this report. The EPSS score of 0.00141 indicates low active exploitation probability; however, the attack surface (maritime vessels) is critically sensitive, and nation-state APT groups targeting maritime infrastructure (e.g., APT28, APT41) have shown historical interest in onboard systems.

Impact Assessment

CVSS breakdown (3.1): AV:N (Network), AC:H (High—requires authenticated low-privilege access and hash exfiltration), PR:L (Low privilege required), UI:N (No user interaction), S:U (Unchanged), C:H (High confidentiality impact), I:N (None), A:N (None). Overall score 5.4 = Medium.

Business impact:

• Voyage data integrity: An attacker able to modify VDR recordings undermines legal compliance (SOLAS Chapter V, Regulation 20 requires mandatory voyage data recording). This can invalidate insurance claims, breach regulatory requirements (IMO), and compromise accident investigations.
• Maritime safety: VDR data is used in casualty investigations (e.g., collision, grounding). Tampering can obscure operational errors, leading to repeated incidents and liability for the vessel operator/manufacturer.
• Intellectual property: VDR contains proprietary routing data, cargo details, and communications logs that could be monetized by commercial espionage actors.
• Regulatory/legal: Non-compliance with IMO cybersecurity guidelines (MSC-FAL.1/Circ.3) and flag-state requirements could result in detention orders, fines, and insurance coverage denial.

Blast radius: Every vessel equipped with the MacGregor G4e VDR (estimated thousands of commercial ships worldwide) running firmware prior to V5.250 is affected. The vulnerability is exploitable remotely if the VDR management interface is exposed to the internet (common on vessels with satellite connectivity and poorly segmented networks), or locally via the shipboard LAN.

Detection Guidance

The following detection rules target anomalous authentication patterns, unauthorized configuration file access, and abnormal network traffic associated with VDR exploitation.

Sigma Rule

title: Danelec VDR G4e - Unauthorized Configuration Backup Access
id: 3d4f7c9a-5d2b-4f8e-b1c0-2a9e6f3d8a5b
status: experimental
description: Detects access to the VDR configuration export endpoint, potentially indicating hash extraction for offline cracking.
logsource:
  category: web_server
  product: apache
  service: access
detection:
  selection:
    cs-method: GET
    cs-uri-stem:
      - /config/export
      - /admin/download/config*
      - /backup/userdb*
    sc-status: 200
  filter:
    src_ip:
      - "10.0.0.0/8"    # Exclude expected internal SCADA network
      - "192.168.0.0/16"
  condition: selection and not filter
fields:
  - clientip
  - cs-uri-stem
  - sc-status
falsepositives:
  - Legitimate system administrator performing routine backups during approved maintenance windows.
level: medium
tags:
  - attack.t1078
  - attack.t1552.001
  - cve.2026-44611

YARA Rule

rule danelec_vdr_hash_extraction
{
    meta:
        author = "ValtersIT Threat Intelligence"
        description = "Detects files containing VDR user credential hashes characteristic of CVE-2026-44611"
        date = "2026-02-15"
        cve = "CVE-2026-44611"
        severity = "medium"

    strings:
        $xml_tag = "<user" ascii wide
        $hash_field = "password_hash" ascii wide
        $hash_md5 = /[a-f0-9]{32}/ ascii
        $hash_sha1 = /[a-f0-9]{40}/ ascii
        $user_db = "user_db" ascii wide
        $vdr_marker = "VDR-G4e" ascii wide
        
    condition:
        all of them and (#hash_md5 > 3 or #hash_sha1 > 3) and #hash_md5 < 50
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-44611 - Danelec VDR configuration export attempt"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/config/export"; nocase; http.uri; content:"/admin/download/"; nocase; pcre:"/(config\.bin|user_db\.xml)$/Ui"; threshold:type limit, track by_src, count 3, seconds 60; classtype:attempted-administrator; sid:202604461; rev:1;)

Elastic Detection

// Detect repeated access to VDR config endpoints from a single source suggesting automated hash harvesting
sequence by source.ip with maxspan=5m
  [network where event.category == "web" and
     url.path == "/config/export" or url.path == "/admin/download/config.bin" or url.path == "/backup/userdb.xml"]
  [network where event.category == "web" and
     url.path == "/config/export" or url.path == "/admin/download/config.bin" or url.path == "/backup/userdb.xml"]

Splunk SPL Query

index=web sourcetype="access_combined"
| where LIKE(uri_path, "%/config/export%") OR LIKE(uri_path, "%/admin/download/%") OR LIKE(uri_path, "%/backup/userdb%")
| stats count, values(status) as http_status, values(uri_path) as paths by src_ip, dest_ip, user
| where count > 2
| eval threat = "CVE-2026-44611 hash extraction attempt"
| table _time, src_ip, dest_ip, user, count, paths, http_status, threat

Wazuh OSSEC Rule

<group name="danelec_vdr,">
  <rule id="446110" level="10" frequency="3" timeframe="120">
    <if_matched_sid>315</if_matched_sid>
    <match>config/export|admin/download/config|backup/userdb</match>
    <description>CVE-2026-44611: Multiple attempts to extract Danelec VDR G4e credential hash database</description>
    <group>attacks, cve-2026-44611, authentication_failure,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 2/4 — CLAIMED (single source claims patch; not independently confirmed by second-party analysis or reproduction).

1. Immediate mitigations (no patch installed yet):

   • Restrict network exposure: Isolate the VDR management interface from public internet access. Implement firewall rules blocking inbound connections to ports 80/443 on the VDR from untrusted networks. If satellite connectivity requires remote management, use VPN (IPsec/OpenVPN) with strong mutual authentication.
   • Change all default credentials immediately: Force password rotation for all accounts. Enforce a minimum length of 12 characters; while the underlying hashing flaw still truncates to 8 chars, an involved defense-in-depth posture reduces risk of trivial guessing.
   • Disable configuration export for non-admin roles: If the firmware allows per-role permissions, restrict the configuration backup functionality to service/admin accounts only.
   • Enable audit logging: Monitor and alert on successful configuration downloads and login anomalies as per the detection rules above.

2. Patch/upgrade steps:

   • Contact Danelec Support (https://www.danelec.com/contact) to request firmware V5.250
   • Firmware update procedure:
     1. Download V5.250 from Danelec FTP/portal (requires authenticated vendor account).
     2. Verify SHA-256 checksum: sha256sum VDR_G4e_V5.250.bin against vendor-issued hash.
     3. Schedule update during vessel port call (requires VDR downtime; log maintenance as per ISO 9001 procedures).
     4. Upload via web UI (/admin/firmware) as a user with service role.
     5. Reboot device and verify firmware version via /api/status endpoint.
   • Post-update verification: Confirm that password_hash fields in exported config now show $6$ (SHA-512 crypt) or $2y$ (bcrypt) prefixed values, indicating the fix is active. Verify password length enforcement.

3. Long-term hardening:

   • Network segmentation: Place VDR on a dedicated OT VLAN with strict ACLs enforced via firewalls (e.g., Tofino, Cisco ISA 3000). Implement IEC 62443-3-3 requirements (SL-2 or higher).
   • Multi-factor authentication: For all interactive VDR access, deploy a reverse proxy (e.g., Apache Guacamole + TOTP) in front of the web interface.
   • Continuous monitoring: Deploy a maritime-specific IDS (e.g., SilentDefense, Nozomi) to monitor VDR network traffic.
   • Password policy enforcement: Remove default accounts entirely; provision individual accounts per crew member within the limits of the VDR's account management.
   • Vendor engagement: Request a CVE-fixed firmware schedule and inquire about future FIPS 140-3 compliant cryptographic implementations.

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2026-44611 — Official CVE details, CVSS v3.1 vector and affected products.
2. CNA Advisory: ICS-CERT Advisory ICSA-26-043-01 (//www.cisa.gov/news-events/ics-advisories/icsa-26-043-01) — Contains vendor fix details and affected version information.
3. Danelec Product Security Page: https://www.danelec.com/security — Vendor security advisories and firmware downloads.
4. MITRE ATT&CK: https://attack.mitre.org/techniques/T1552/001/ — Unsecured Credentials: Credentials In Files, corresponding to the hash extraction phase.
5. CWE-916 Reference: https://cwe.mitre.org/data/definitions/916.html — Use of Password Hash With Insufficient Computational Effort.

Known threat actor campaigns: No documented in-the-wild exploitation as of the publication date of this report. The EPSS score (0.00141, 3.9th percentile) confirms low active exploitation probability. However, the vulnerable device class (maritime ICS) is a known target for state-sponsored cyber espionage (e.g., Iran's APT234 targeting shipping; China's APT41 targeting maritime logistics) and criminal ransomware groups (e.g., Ryuk affiliates targeting port infrastructure). Organizations operating VDR G4e should treat this as a high-priority remediation due to vessel criticality despite the medium CVSS score.