How to remediate – Apache Kylin Web UI Detection

1. Introduction

The web user interface for Apache Kylin was detected on the remote host. This means an administration portal is exposed, potentially allowing unauthorized access to system settings and data. Affected systems are typically those running Apache Kylin, a distributed analytics engine designed for large datasets. A successful exploit could lead to information disclosure or modification of system configurations.

2. Technical Explanation

The vulnerability stems from the presence of an exposed web UI that may not have appropriate security controls enabled by default. An attacker can access this interface remotely if it is reachable over a network connection. There is no known CVE associated with simply detecting the UI, but its presence indicates a potential risk requiring investigation and mitigation.

• Root cause: The Apache Kylin web UI is running and accessible without sufficient authentication or authorization.
• Exploit mechanism: An attacker could attempt to access the UI directly via a web browser and potentially exploit default credentials, known vulnerabilities in the UI itself, or misconfigured settings.
• Scope: Systems running Apache Kylin versions with an enabled web UI are affected.

3. Detection and Assessment

Confirming whether a system is vulnerable involves checking for the presence of the web UI and assessing its security configuration.

• Quick checks: Use curl or a web browser to access the default Kylin UI port (typically 8080). A successful connection indicates the UI is running.
• Scanning: Nessus plugin ID 139625 can detect the Apache Kylin Web UI. This should be used as an example only, and results verified manually.
• Logs and evidence: Check web server logs for access attempts to the Kylin UI port (8080).

curl http://<target_ip>:8080

4. Solution / Remediation Steps

The primary solution is to secure or disable the Apache Kylin web UI if it’s not required.

4.1 Preparation

• Services: Stop the Apache Kylin service if disabling the UI. A roll back plan involves restarting the service.
• Dependencies: Ensure no other applications depend on the Kylin UI. Change windows may be needed for production systems, requiring approval from IT management.

4.2 Implementation

1. Step 1: If the UI is not required, stop the Apache Kylin web server process.
2. Step 2: Configure Apache Kylin to disable the web UI by modifying the kylin_job_white_list property in the kylin.properties file. Set this value to an empty string.
3. Step 3: Restart the Apache Kylin service for changes to take effect.

4.3 Config or Code Example

Before

kylin.job.white_list=127.0.0.1,::1

After

kylin.job.white_list=

4.4 Security Practices Relevant to This Vulnerability

List only practices that directly address this vulnerability type. Use neutral wording and examples instead of fixed advice.

• Least privilege: Restrict access to the Kylin UI to authorized users only.

4.5 Automation (Optional)

If suitable, provide a small script or infrastructure code that applies the fix at scale. Only include if safe and directly relevant.

# Example Bash script to disable Kylin UI (requires sudo access)
sudo systemctl stop kylin
sudo sed -i 's/kylin.job.white_list=.*/kylin.job.white_list=/g' /path/to/kylin.properties
sudo systemctl start kylin

5. Verification / Validation

Confirm the fix worked by checking that the UI is no longer accessible or requires authentication.

• Post-fix check: Use curl http://<target_ip>:8080. A connection timeout or an authentication prompt indicates success.
• Re-test: Re-run the initial curl command to verify the UI is inaccessible.
• Smoke test: Verify other Kylin functionalities (e.g., query execution) are still working as expected.
• Monitoring: Monitor web server logs for any unexpected access attempts to port 8080.

curl http://<target_ip>:8080

6. Preventive Measures and Monitoring

Suggest only measures that are relevant to the vulnerability type. Use “for example” to keep advice conditional, not prescriptive.

• Baselines: Update security baselines to include a requirement for disabling unnecessary web UIs or enforcing strong authentication.
• Pipelines: Integrate static analysis tools into CI/CD pipelines to identify potentially exposed services and misconfigurations.
• Asset and patch process: Review system configurations regularly to ensure compliance with security policies.

7. Risks, Side Effects, and Roll Back

• Risk or side effect 1: Disabling the UI may impact users who rely on it for administration.
• Risk or side effect 2: Incorrect configuration changes could prevent Kylin from starting.
• Roll back: Restore the original kylin.properties file and restart the Apache Kylin service.

8. References and Resources

Link only to sources that match this exact vulnerability. Use official advisories and trusted documentation.

• Vendor advisory or bulletin: https://kylin.apache.org/