How to remediate – Apple AirPort Base Station Authentication Credential Encryptio…

1. Introduction

The Apple AirPort Base Station Authentication Credential Encryption vulnerability (CVE-2003-0270) is a design flaw in the administrative protocol of Apple Airport Wireless Access Points. This allows attackers sniffing network traffic to potentially gain administrative access by intercepting passwords sent in cleartext. Systems affected are those running vulnerable versions of Apple AirPort base station firmware. A successful exploit could lead to complete compromise of the wireless access point, impacting confidentiality, integrity and availability.

2. Technical Explanation

The vulnerability stems from a weakness in how passwords are encrypted when connecting to TCP port 5009 for administration. The password is sent with only slight obfuscation, making it vulnerable to interception. An attacker on the same network segment can passively capture this traffic and recover the administrative credentials. This allows them to gain full control of the base station without any prior authentication.

• Root cause: Passwords are transmitted in cleartext (with minimal obfuscation) over TCP port 5009 during administration.
• Exploit mechanism: An attacker uses a packet sniffer (like Wireshark) to capture network traffic on port 5009, then extracts the password from intercepted packets.
• Scope: Apple Airport Wireless Access Points are affected. Specific firmware versions were not explicitly stated in the provided context.

3. Detection and Assessment

To confirm vulnerability, check if the base station is accessible on port 5009 and monitor network traffic for cleartext password transmissions.

• Quick checks: Use `telnet 5009` to see if a connection can be established.
• Scanning: Nessus plugin ID 13864 may detect this vulnerability, but results should be verified manually.
• Logs and evidence: Airport base stations do not keep logs of administrative access attempts, making detection difficult without network traffic analysis.

telnet  5009

4. Solution / Remediation Steps

To fix this issue, block incoming traffic to port 5009 and administer the base station only via a direct Ethernet connection.

4.1 Preparation

• This change requires a maintenance window as it may temporarily disrupt remote administration access. Approval from the network administrator is recommended.

4.2 Implementation

1. Step 1: Block incoming traffic to TCP port 5009 on your firewall or router.
2. Step 2: Connect an Ethernet cable directly between your computer and the Airport Base Station for administration.

4.3 Config or Code Example

Before

# No firewall rule blocking port 5009 (example)
iptables -L | grep 5009 # Should show no relevant rules

After

# Firewall rule blocking incoming traffic on port 5009 (example)
iptables -A INPUT -p tcp --dport 5009 -j DROP
iptables-save # Save the firewall rules to make them persistent

4.4 Security Practices Relevant to This Vulnerability

Several security practices can help prevent this type of issue. Least privilege reduces the impact if an attacker gains access. Secure defaults, like disabling remote administration by default, also improve security. A strong patch cadence ensures timely updates and fixes for known vulnerabilities.

• Practice 1: Implement least privilege to limit the damage caused by a compromised account.
• Practice 2: Disable unnecessary services, such as remote administration when not in use.

4.5 Automation (Optional)

If you manage your firewall with Ansible, you could automate blocking port 5009.

---
- hosts: firewalls
  tasks:
    - name: Block incoming traffic on port 5009
      iptables:
        chain: INPUT
        protocol: tcp
        destination_port: 5009
        jump: DROP
        state: present

5. Verification / Validation

Confirm the fix by verifying that port 5009 is blocked and attempting to connect remotely. A negative test should fail, while a direct Ethernet connection should succeed.

• Post-fix check: `telnet 5009` should time out or be refused.
• Re-test: Run the earlier quick check (port 5009 connectivity) and confirm it fails.
• Smoke test: Verify you can still administer the base station via a direct Ethernet connection.
• Monitoring: Monitor firewall logs for blocked connections on port 5009 as an indicator of attempted exploitation.

telnet  5009 # Should time out or be refused

6. Preventive Measures and Monitoring

Update security baselines to include blocking unnecessary ports like 5009. Implement vulnerability scanning in your CI/CD pipelines to detect similar issues early on. Maintain a regular patch review cycle for all network devices.

• Baselines: Update your firewall baseline or security policy to block incoming traffic on port 5009 by default.
• Pipelines: Add vulnerability scanning tools to your CI/CD pipeline that can detect open ports and known vulnerabilities in network device configurations.
• Asset and patch process: Review firmware updates for Apple Airport Base Stations at least quarterly, or more frequently if security advisories are released.

7. Risks, Side Effects, and Roll Back

Blocking port 5009 prevents remote administration. The roll back steps involve removing the firewall rule blocking port 5009.

• Risk or side effect 1: Remote administration will be unavailable until the firewall rule is removed.
• Roll back:
  1. Step 1: Remove the iptables rule blocking incoming traffic on port 5009 using `iptables -D INPUT -p tcp –dport 5009 -j DROP`.
  2. Step 2: Save the firewall rules with `iptables-save`.

8. References and Resources

• Vendor advisory or bulletin: No link provided in context.
• NVD or CVE entry: CVE-2003-0270
• Product or platform documentation relevant to the fix: No link provided in context.