How to remediate – Wireless Access Point Detection

1. Introduction

The Wireless Access Point Detection vulnerability means Nessus has identified a wireless access point on your network. This is important because a misconfigured AP could allow unauthorised access to internal systems. Systems usually affected are any devices acting as a Wi-Fi hotspot, including dedicated access points and routers with wireless capabilities. A likely impact is the compromise of data confidentiality, integrity, and availability if an attacker gains network access through the vulnerable device.

2. Technical Explanation

This vulnerability indicates that a host is functioning as a wireless access point. Attackers can exploit this by attempting to connect to the AP using weak or default credentials, or by exploiting vulnerabilities in the AP’s firmware. Successful exploitation allows them to gain a foothold on your internal network without physical presence. The preconditions for exploitation include an active wireless access point and potentially weak security settings.

• Root cause: The host is operating as a wireless access point, which presents a potential attack surface if not properly secured.
• Exploit mechanism: An attacker could attempt to connect to the AP using default credentials or exploit known vulnerabilities in its firmware. For example, an attacker might use tools like Aircrack-ng to crack WEP encryption.
• Scope: Any device configured as a wireless access point is affected, regardless of manufacturer or operating system. Older devices with outdated firmware are particularly vulnerable.

3. Detection and Assessment

You can confirm the presence of an AP by checking network interfaces and scanning for rogue access points. A quick check involves listing active Wi-Fi networks on a client machine. Thorough assessment requires using a dedicated wireless intrusion detection system (WIDS).

• Quick checks: On Windows, use netsh wlan show all to list connected and available wireless networks.
• Scanning: Nessus vulnerability ID 10429 can identify APs on the network. Other scanners like Kismet or Wireshark can also detect wireless traffic.
• Logs and evidence: Check firewall logs for connections to unknown SSIDs or MAC addresses associated with access points. Event IDs related to wireless network activity may be useful.

netsh wlan show all

4. Solution / Remediation Steps

To fix this, ensure the AP is properly secured and monitored. This involves changing default credentials, enabling strong encryption, and regularly updating firmware. Only apply these steps to access points you manage.

4.1 Preparation

• Ensure you have the latest firmware available for your specific AP model. A roll back plan involves restoring from the backup configuration.
• Change windows should be planned and approved by a senior IT administrator.

4.2 Implementation

1. Step 1: Change the default administrative password on the access point to a strong, unique password.
2. Step 2: Enable WPA3 encryption if your devices support it; otherwise, use WPA2 with AES encryption. Avoid using WEP or TKIP.
3. Step 3: Disable SSID broadcasting to hide the network name.
4. Step 4: Enable MAC address filtering to allow only known devices to connect (optional).
5. Step 5: Update the AP’s firmware to the latest version from the vendor’s website.

4.3 Config or Code Example

Before

# Default configuration (example)
SSID: MyNetwork
Encryption: WEP
Password: password123
Admin Password: admin

After

# Secure configuration (example)
SSID: MyNetwork
Encryption: WPA3
Password: StrongUniquePassword
Admin Password: VeryStrongPassword
MAC Filtering: Enabled (with allowed MAC addresses)

4.4 Security Practices Relevant to This Vulnerability

Several security practices can help prevent this issue. Least privilege limits the impact of a compromised AP. Secure defaults ensure strong settings from installation. Regular patch cadence keeps firmware up-to-date with the latest security fixes.

• Practice 1: Implement least privilege by restricting access to the AP’s management interface.
• Practice 2: Enforce secure defaults, such as WPA3 encryption and strong passwords, during initial configuration.

4.5 Automation (Optional)

Automation is difficult without a specific AP management system. However, you could use scripting to periodically check for firmware updates on known devices. This requires vendor-specific APIs or command-line tools.

# Example PowerShell script (requires vendor API)
# Get list of managed APs
# Check current firmware version
# Compare against latest available version
# If update needed, trigger update process

5. Verification / Validation

• Post-fix check: Use netsh wlan show interfaces on a client machine to confirm WPA3 or WPA2 encryption is enabled for the AP’s SSID.
• Re-test: Re-run the Nessus scan (ID 10429) and verify that no vulnerabilities are reported.
• Smoke test: Ensure users can still connect to the Wi-Fi network and access internet resources.
• Monitoring: Monitor firewall logs for any unusual wireless activity or connection attempts from unknown MAC addresses.

netsh wlan show interfaces

6. Preventive Measures and Monitoring

Update security baselines to include strong Wi-Fi settings. Implement checks in CI/CD pipelines to ensure AP configurations meet security standards. Establish a regular patch or configuration review cycle for all network devices.

• Baselines: Update your wireless security baseline to require WPA3 encryption, strong passwords, and disabled SSID broadcasting.
• Asset and patch process: Review AP firmware versions monthly and apply updates promptly.

7. Risks, Side Effects, and Roll Back

Changing encryption settings can cause compatibility issues with older devices. Incorrect configuration may prevent users from connecting to the network. Roll back by restoring the backup configuration.

• Risk or side effect 1: Older devices may not support WPA3 encryption, requiring you to use WPA2 instead.

8. References and Resources

• Vendor advisory or bulletin: Check your AP manufacturer’s website for security advisories related to wireless access point configuration.
• NVD or CVE entry: https://nvd.nist.gov/vuln/detail/CVE-2017-13859 (example – WPA vulnerability)
• Product or platform documentation relevant to the fix: Refer to your AP’s user manual for instructions on changing passwords, enabling encryption, and updating firmware.