How to remediate – HTTP TRACE / TRACK Methods Allowed

1. Introduction

The HTTP TRACE / TRACK Methods Allowed vulnerability means debugging functions are active on a web server. This allows attackers to gather information about the server and potentially bypass security measures. Affected systems are typically web servers running Apache, Oracle, and other common platforms. A successful exploit could lead to information disclosure and potential compromise of confidentiality, integrity, and availability.

2. Technical Explanation

The remote web server supports the TRACE or TRACK HTTP methods. These methods are designed for debugging purposes but can be misused by attackers to retrieve sensitive data like headers, cookies, and internal server information. An attacker could send a TRACE request to the server and examine the response to gather details about its configuration and environment. CVE-2003-1567, CVE-2004-2320, and CVE-2010-0386 describe this issue.

• Root cause: The server incorrectly handles HTTP TRACE or TRACK requests, not restricting access to authorized users.
• Exploit mechanism: An attacker sends a TRACE/TRACK request and analyses the response headers for sensitive information. For example, an attacker could send TRACE / HTTP/1.0 and examine the Via header.
• Scope: Apache web servers, Oracle application servers, and other platforms that support HTTP TRACE or TRACK methods are affected.

3. Detection and Assessment

You can confirm a vulnerability by checking if your server responds to TRACE/TRACK requests. A thorough method involves using a dedicated security scanner.

• Quick checks: Use curl -v http://yourserver.com/ and look for support of the TRACE or TRACK methods in the response headers.
• Scanning: Nessus plugin ID 979b5cb can detect this vulnerability. Other scanners may have similar signatures.
• Logs and evidence: Check web server access logs for TRACE or TRACK requests. Look for unusual activity or unexpected responses.

curl -v http://yourserver.com/

4. Solution / Remediation Steps

Disable the HTTP TRACE and TRACK methods on your web server to fix this issue.

4.1 Preparation

• Ensure you have access to modify the web server configuration file. A roll back plan is to restore the original configuration file.
• Change windows may be needed for production systems and should be approved by relevant teams.

4.2 Implementation

1. Step 1: Edit your web server’s main configuration file (e.g., httpd.conf, apache2.conf).
2. Step 2: Add or modify the following line to disable TRACE and TRACK methods: TraceEnable Off.
3. Step 3: Restart the web service for the changes to take effect.

4.3 Config or Code Example

Before

# No explicit TraceEnable directive, meaning TRACE is enabled by default

After

TraceEnable Off

4.4 Security Practices Relevant to This Vulnerability

Several security practices can help prevent this issue.

• Least privilege: Restrict access to debugging functions to authorized users only, reducing the impact if exploited.
• Safe defaults: Configure web servers with secure settings by default, disabling unnecessary features like TRACE and TRACK methods.

4.5 Automation (Optional)

If using a configuration management tool, you can automate this change.

# Example Ansible task to disable TraceEnable in Apache config
- name: Disable HTTP TRACE method
  lineinfile:
    path: /etc/apache2/apache2.conf
    regexp: '^TraceEnable'
    line: 'TraceEnable Off'
    state: present
  notify: Restart Apache

5. Verification / Validation

Confirm the fix by checking if your server no longer responds to TRACE/TRACK requests.

• Post-fix check: Run curl -v http://yourserver.com/ and verify that the response does not include support for TRACE or TRACK methods.
• Re-test: Re-run the initial curl command to confirm that the server no longer responds to TRACE requests.
• Smoke test: Verify that standard web functionality (e.g., accessing a website) still works as expected.
• Monitoring: Monitor web server access logs for any unexpected TRACE or TRACK requests, which could indicate an attempted exploit.

curl -v http://yourserver.com/

6. Preventive Measures and Monitoring

Update security baselines to include disabling HTTP TRACE and TRACK methods.

• Baselines: Update your web server security baseline or policy to explicitly disable the TRACE and TRACK methods.
• Pipelines: Add checks in CI/CD pipelines to ensure that new configurations do not enable these methods.
• Asset and patch process: Implement a regular review cycle for web server configurations to identify and address potential vulnerabilities.

7. Risks, Side Effects, and Roll Back

Disabling TRACE/TRACK should have minimal impact on standard web functionality.

• Roll back: Restore the original web server configuration file and restart the service to re-enable TRACE/TRACK methods if necessary.

8. References and Resources

Links to official advisories and documentation.

• Vendor advisory or bulletin: http://www.apacheweek.com/issues/03-01-24
• NVD or CVE entry: CVE-2003-1567
• Product or platform documentation relevant to the fix: https://download.oracle.com/sunalerts/1000718.1.html