1. Introduction
The Password Submitted Using GET Method vulnerability occurs when an application transmits passwords via the HTTP GET method instead of POST. This exposes sensitive credentials in server logs, browser history, and potentially to third parties through referrer headers. It affects web applications that handle user authentication, with a likely impact on confidentiality, integrity, and availability if exploited.
2. Technical Explanation
The root cause is the use of HTTP GET requests for password submission instead of the more secure POST method. An attacker can exploit this by intercepting the URL containing the password or finding it in server logs. The preconditions include a vulnerable web application and an ability to observe network traffic or access log files. A simple example would be an attacker gaining access to a proxy server log where the URL with the password is recorded during login.
- Root cause: Use of HTTP GET for transmitting sensitive data, specifically passwords.
- Exploit mechanism: An attacker intercepts the URL containing the password via network sniffing or by accessing web server logs. For example, a user logs in and the URL `https://example.com/login?password=user_password` is logged.
- Scope: Web applications using HTTP GET for login forms are affected.
3. Detection and Assessment
To confirm vulnerability, first check if password submission uses GET requests. A thorough method involves intercepting network traffic during a login attempt.
- Quick checks: Inspect the browser’s developer tools (Network tab) to see how the login form data is sent. Look for passwords in URL query parameters.
- Scanning: Burp Suite or OWASP ZAP can identify this vulnerability by intercepting and analysing web traffic during authentication.
- Logs and evidence: Check web server access logs for URLs containing “password” as a parameter.
curl -v https://example.com/login?username=test&password=password4. Solution / Remediation Steps
To fix this issue, change password submission to use the HTTP POST method.
4.1 Preparation
- Ensure developers understand the implications of changing request methods. Change windows may be required for production systems, with approval from security or IT management.
4.2 Implementation
- Step 1: Modify the application’s login form to use POST instead of GET.
- Step 2: Update server-side code to handle password submission via POST requests.
- Step 3: Test the updated login functionality thoroughly with various inputs and scenarios.
4.3 Config or Code Example
Before
<form action="login" method="GET">After
<form action="login" method="POST">4.4 Security Practices Relevant to This Vulnerability
Input validation and secure defaults are key practices for preventing this issue.
- Practice 2: Secure defaults should be configured to use POST for sensitive forms and transactions.
4.5 Automation (Optional)
Automation may not directly apply here as it requires code changes. However, static analysis tools can identify uses of GET for password submission.
5. Verification / Validation
Confirm the fix by verifying that passwords are no longer transmitted in URLs. Re-test using the earlier detection methods to confirm the issue is resolved.
- Post-fix check: Inspect browser developer tools (Network tab) during login; passwords should be sent as POST data, not URL parameters.
- Re-test: Run the `curl` command from section 3 and verify that the password is no longer visible in the URL.
- Monitoring: Check web server logs for any remaining instances of passwords in URLs as a regression indicator.
curl -v https://example.com/login?username=test&password=password6. Preventive Measures and Monitoring
Update security baselines to enforce POST for sensitive forms, and add checks in CI pipelines to detect GET requests for password submission.
- Baselines: Update web application security standards to require the use of POST for all password submissions.
- Pipelines: Implement static analysis tools (SAST) that flag uses of HTTP GET for sensitive data transmission during development.
- Asset and patch process: Review code changes regularly to ensure adherence to secure coding practices, including proper request method usage.
7. Risks, Side Effects, and Roll Back
Changing the request method may require updates to client-side code or integrations that rely on the GET parameter format. Roll back by restoring the original application code and configuration.
- Roll back: Restore the backed-up application code and configuration files. Restart the web service.
8. References and Resources
- Vendor advisory or bulletin: N/A
- NVD or CVE entry: N/A
- Product or platform documentation relevant to the fix: https://owasp.org/www-community/vulnerabilities/Information_exposure_through_query_strings_in_url