Remediation/Mitigation Strategy: CVE-2025-27500 - OpenZiti Stored Cross-Site Scripting (XSS)

This document outlines the remediation and mitigation strategy for CVE-2025-27500, a stored Cross-Site Scripting (XSS) vulnerability in OpenZiti.

1. Vulnerability Description:

• Vulnerability: Stored Cross-Site Scripting (XSS)
• Affected Software: OpenZiti versions prior to 3.7.1
• Location: /api/upload endpoint on the admin panel
• Description: An unauthenticated endpoint (/api/upload) on the OpenZiti admin panel allows arbitrary file uploads via HTTP POST. These uploaded files are stored on the node and accessible via a URL. If a malicious file containing JavaScript code (e.g., a specially crafted HTML file) is uploaded, it can be executed within the browser context of any user who accesses the file’s URL, leading to a stored XSS attack.

2. Severity:

• CVSS v3.1 Score: 8.2 (High)
• Vector String: AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
• Explanation:
  • AV:N (Network): The attack can be launched remotely over the network.
  • AC:L (Low): The attack requires minimal effort to exploit.
  • PR:N (None): No privileges are required to exploit the vulnerability (unauthenticated).
  • UI:R (Requires User Interaction): The vulnerability requires a user to interact with the malicious content (accessing the uploaded file’s URL).
  • S:C (Changed): The security scope is changed; the attack executes in the context of a different domain (the OpenZiti domain), allowing for credential theft, session hijacking, and other malicious actions.
  • C:H (High): High impact to confidentiality. Attacker can access sensitive information.
  • I:H (High): High impact to integrity. Attacker can modify data or perform actions on behalf of the user.
  • A:N (None): No impact to availability. The system remains available.

3. Known Exploits:

• An attacker can upload a malicious HTML or JavaScript file containing XSS payloads.
• This malicious file is stored on the OpenZiti node and assigned a public URL.
• When a user (e.g., an administrator) accesses the URL of the malicious file through their browser, the embedded JavaScript code is executed within their browser context.
• The attacker can then:
  • Steal session cookies and hijack the user’s session.
  • Deface the web application.
  • Redirect the user to a phishing website.
  • Execute arbitrary commands on the user’s browser and potentially on the user’s system.
  • Exfiltrate sensitive data.

4. Remediation Steps:

The primary remediation is to upgrade OpenZiti to version 3.7.1 or later. This version disables the vulnerable /api/upload endpoint.

• Step 1: Upgrade OpenZiti: Immediately upgrade all OpenZiti deployments to version 3.7.1 or later. Follow the official OpenZiti upgrade documentation for your specific deployment method.

  # Example (replace with your actual upgrade process)
  

  Assuming you are using a package manager like apt:

  sudo apt update sudo apt upgrade openziti

• Step 2: Verify the Upgrade: After upgrading, verify that the /api/upload endpoint is no longer accessible or functional. Attempting to access it should result in an error (e.g., a 404 Not Found).

• Step 3: Scan for Malicious Files (if possible): If you suspect that the vulnerability has been exploited, scan the OpenZiti node’s file system for any unusual or suspicious files that may have been uploaded to the directory where the uploaded files were stored. This might be difficult without knowing the exact storage location used by the vulnerable endpoint.

• Step 4: Review Audit Logs: Examine OpenZiti’s audit logs for any suspicious activity, such as unusual file upload attempts or accesses to unknown files. Look for patterns of access to files that might indicate an XSS exploit.

5. Mitigation Steps (If Immediate Upgrade is Not Possible):

If you cannot immediately upgrade to version 3.7.1, implement the following mitigation steps:

• Option 1 (Recommended if possible): Disable the /api/upload Endpoint: Manually disable the /api/upload endpoint in your OpenZiti configuration. This might involve modifying your web server configuration (e.g., Nginx, Apache) or modifying the OpenZiti application code directly (if feasible). The specific method will depend on how OpenZiti is deployed.

• Option 2 (Least Effective, Use with Extreme Caution): Implement Access Controls: Restrict access to the admin panel to only trusted users. This does not eliminate the vulnerability, but it reduces the attack surface by limiting the number of users who could potentially be affected.

6. Communication:

• Communicate the vulnerability and the remediation/mitigation steps to all relevant stakeholders (system administrators, security teams, and OpenZiti users).
• Provide clear instructions on how to upgrade OpenZiti or implement the mitigation steps.

7. Monitoring:

• Continuously monitor OpenZiti systems for any signs of suspicious activity.
• Implement intrusion detection and prevention systems (IDS/IPS) to detect and block potential XSS attacks.

8. Long-Term Recommendations:

• Implement a vulnerability management program to proactively identify and address security vulnerabilities in OpenZiti and other software.
• Ensure that OpenZiti and other software are regularly updated with the latest security patches.
• Educate users about the risks of XSS attacks and how to avoid them.
• Implement robust access controls and authentication mechanisms to protect sensitive data and systems.
• Consider using a web application firewall (WAF) to protect OpenZiti from common web attacks, including XSS.

Disclaimer: This remediation/mitigation strategy is based on the information provided in the security advisory. It is important to consult the official OpenZiti documentation and security advisories for the most accurate and up-to-date information. The effectiveness of these steps depends on your specific environment and implementation. Always test changes in a non-production environment before deploying them to production.

Assigner

• GitHub, Inc. [email protected]

Date

• Published Date: 2025-03-03 19:15:36
• Updated Date: 2025-03-03 19:15:36

More Details

CVE-2025-27500