1. Introduction
Piwik Detection identifies instances of the Piwik web analytics tool running on a remote server. Piwik, now known as Matomo, is used to track website visitor behaviour and generate detailed reports. Its presence can indicate data collection practices that may require review for compliance with privacy regulations like GDPR. A successful exploit could lead to information disclosure or modification of tracked data.
2. Technical Explanation
The vulnerability isn’t a flaw in Piwik itself, but the fact of its installation and operation. An attacker gaining access to the server hosting Piwik can potentially compromise the analytics data, modify tracking configurations, or use it as a foothold for further attacks on the webserver. Preconditions include network accessibility to the Piwik instance and valid credentials (or an exploitable vulnerability in the webserver itself). There is no specific CVE associated with simply running Piwik.
- Root cause: The presence of a third-party application collecting and storing potentially sensitive data.
- Exploit mechanism: An attacker could exploit vulnerabilities within the Piwik installation or the underlying web server to gain access to the database containing analytics information. For example, an SQL injection attack against a poorly secured Piwik instance.
- Scope: Any system running a vulnerable version of Matomo (formerly Piwik).
3. Detection and Assessment
Confirming the presence of Piwik can be done quickly through web server inspection or by checking for specific files. A thorough assessment involves identifying the version and configuration.
- Quick checks: Check the website’s robots.txt file for references to /piwik/ or /matomo/. Inspect HTTP headers for clues about analytics software in use.
- Scanning: Nessus plugin ID 168347 can identify Piwik installations. OpenVAS also has relevant scans, but results may vary.
- Logs and evidence: Web server access logs may show requests to /piwik/ or /matomo/. Application logs (if accessible) might contain information about Matomo activity.
curl -I https://example.com/piwik/ | grep "X-Powered-By"4. Solution / Remediation Steps
The primary solution is to assess the need for Piwik and, if not required, remove it. If needed, ensure it’s kept up to date with security patches.
4.1 Preparation
- Services: Stop the webserver service if removing Piwik files directly.
- Roll back plan: Restore the web server from the backup taken in the previous step.
4.2 Implementation
- Step 1: If Piwik is no longer needed, delete the entire Piwik directory from the webserver.
- Step 2: Remove any associated database tables or entries if applicable.
- Step 3: Update website configuration files to remove references to Piwik scripts or tracking URLs.
4.3 Config or Code Example
Before
<script src="https://example.com/piwik/piwik.js" type="text/javascript"></script>After
4.4 Security Practices Relevant to This Vulnerability
- Least privilege: Limit access to the web server and database hosting Piwik to only authorized personnel.
- Patch cadence: Regularly update all software, including Matomo, with security patches.
4.5 Automation (Optional)
No automation is recommended for removal due to potential impact on website functionality.
5. Verification / Validation
Confirm the fix by checking that Piwik files are no longer accessible and that tracking scripts have been removed from the website.
- Post-fix check: Attempt to access https://example.com/piwik/. You should receive a 404 error or similar indicating the resource is not found.
- Re-test: Re-run the curl command from Section 3. It should no longer show any Piwik references.
- Monitoring: Monitor web server access logs for any unexpected requests to /piwik/ or /matomo/.
curl -I https://example.com/piwik/6. Preventive Measures and Monitoring
- Baselines: Include Piwik (Matomo) in your application inventory baseline, with a requirement for regular security reviews.
- Pipelines: Implement static code analysis to identify hardcoded tracking URLs or scripts.
- Asset and patch process: Review all third-party applications regularly for updates and vulnerabilities.
7. Risks, Side Effects, and Roll Back
- Risk or side effect 1: Removing Piwik may disrupt website analytics if not properly planned.
8. References and Resources
- Vendor advisory or bulletin: https://matomo.org/security/
- NVD or CVE entry: Not applicable, as this is not a specific vulnerability in Piwik itself.
- Product or platform documentation relevant to the fix: https://matomo.org/docs/