How to remediate – Novatel MiFi Detection

1. Introduction

The Novatel MiFi Detection vulnerability identifies systems running a Novatel MiFi device, a portable internet access point using cellular data connections. These devices can introduce security risks if used without proper controls, potentially allowing unauthorized network access. This impacts confidentiality, integrity and availability of the networks they connect to.

2. Technical Explanation

The vulnerability is not an exploitable flaw in the MiFi device itself, but rather its presence on a network which may be unexpected or unauthorised. MiFi devices typically operate as routers with default configurations that may not align with organisational security standards. An attacker could exploit weak or default settings to gain access to the connected network.

• Root cause: The device is present and potentially operating with insecure defaults.
• Exploit mechanism: An attacker connects to a MiFi’s wireless network, then attempts to access its web interface using default credentials (often admin/admin or no password). Successful login allows modification of settings like the firewall, Wi-Fi password, or connected devices.
• Scope: Novatel Wireless MiFi devices across various models and firmware versions are affected.

3. Detection and Assessment

Confirming a MiFi device’s presence requires network scanning and analysis of wireless access points. A quick check involves identifying the manufacturer’s OUI (Organisationally Unique Identifier). More thorough methods include examining DHCP leases or using dedicated network discovery tools.

• Quick checks: Use arp -a on a connected network segment to list MAC addresses and identify those belonging to Novatel Wireless (OUI range is typically 00:1A:22).
• Scanning: Nmap can be used with the following script: nmap --script broadcast-dns --script http-title -p 80,443 . Look for responses indicating a Novatel MiFi web interface.
• Logs and evidence: Examine DHCP server logs for leases assigned to MAC addresses belonging to Novatel Wireless. Check wireless access point lists for devices with names like “MiFi” or similar.

arp -a

4. Solution / Remediation Steps

Remediating this vulnerability involves ensuring the use of MiFi devices aligns with your organisation’s security policies and acceptable use guidelines. This may include restricting their use, requiring specific configurations, or implementing network segmentation.

4.1 Preparation

• No services need to be stopped. A roll back plan involves reverting any implemented restrictions or policies.
• Changes may require approval from the IT security team depending on organisational procedures.

4.2 Implementation

1. Step 1: Review your organisation’s acceptable use policy and update it to specifically address personal MiFi devices if necessary.
2. Step 2: Implement network access controls (NAC) or firewall rules to restrict or monitor traffic from unknown wireless access points.
3. Step 3: Educate users about the risks of using unmanaged MiFi devices on the corporate network.

4.3 Config or Code Example

Before

# No restrictions on wireless access points

After

# Firewall rule blocking traffic from unknown MAC addresses (e.g., not in approved list)
iptables -A INPUT -m mac --mac-source ! 00:1A:22:XX:XX:XX -j DROP

4.4 Security Practices Relevant to This Vulnerability

Several security practices can mitigate the risks associated with unmanaged devices on your network. These include least privilege, network segmentation and asset inventory.

• Practice 1: Least privilege access limits the potential damage if a MiFi device is compromised.
• Practice 2: Network segmentation isolates potentially vulnerable devices from critical systems.

4.5 Automation (Optional)

# Example Ansible playbook to block unknown MAC addresses on firewall
- name: Block unknown MAC addresses
  iptables:
    chain: INPUT
    mac_source: '!'
    state: present

5. Verification / Validation

Confirming the fix involves verifying that network access controls are correctly blocking traffic from unapproved MiFi devices. Re-run the detection methods to ensure no unauthorized devices are present. A simple smoke test confirms normal network connectivity for authorized users and systems.

• Post-fix check: Run arp -a again and confirm that any previously identified Novatel MiFi MAC addresses are no longer visible on the network, or are subject to restricted access.
• Re-test: Re-run the Nmap scan from section 3 and verify it does not detect any active MiFi devices.
• Smoke test: Confirm users can still access essential services like email and file shares.
• Monitoring: Monitor firewall logs for blocked connections originating from unknown MAC addresses, indicating potential unauthorized device activity.

arp -a

6. Preventive Measures and Monitoring

Preventive measures include regularly updating security baselines and incorporating checks into CI/CD pipelines to identify unapproved devices. A sensible patch or config review cycle should be established based on the risk profile of your organisation.

• Baselines: Update network security baselines to explicitly define approved wireless access point types and MAC addresses.
• Pipelines: Add checks in CI/CD pipelines to scan for rogue devices during deployment or configuration changes.
• Asset and patch process: Implement a regular review cycle (e.g., monthly) of network device inventory and configurations.

7. Risks, Side Effects, and Roll Back

Blocking traffic from MiFi devices may inadvertently block legitimate users if their devices are incorrectly identified. Service impacts could include temporary loss of connectivity for affected users. Roll back involves removing the implemented restrictions or firewall rules.

• Risk or side effect 1: False positives blocking legitimate devices. Mitigation: Carefully define approved MAC address ranges and provide a process for whitelisting exceptions.
• Risk or side effect 2: Temporary connectivity loss for affected users. Mitigation: Communicate changes in advance and provide support for troubleshooting connection issues.
• Roll back: Step 1: Remove the firewall rule added in section 4.2 using iptables -D INPUT -m mac --mac-source ! 00:1A:22:XX:XX:XX -j DROP.

8. References and Resources

• Vendor advisory or bulletin: Novatel Wireless Support
• NVD or CVE entry: Not applicable, as this is a policy issue rather than a specific vulnerability.
• Product or platform documentation relevant to the fix: Netgear MiFi Configuration (example of changing default settings).