CVE-2025-54056: HTML5 Audio Player PRO XSS Vulnerability

CVE-2025-54056 Overview

CVE-2025-54056 is a reflected Cross-Site Scripting (XSS) vulnerability in the LambertGroup Responsive HTML5 Audio Player PRO With Playlist WordPress plugin (lbg-audio2-html5). The flaw stems from improper neutralization of user-supplied input during web page generation [CWE-79]. It affects all plugin versions up to and including 3.5.8. An unauthenticated attacker can craft a malicious URL that, when clicked by a victim, executes arbitrary JavaScript in the victim's browser within the context of the vulnerable site.

Critical Impact

Successful exploitation lets attackers execute arbitrary JavaScript in a victim's browser session, enabling session theft, credential harvesting, and redirection to attacker-controlled infrastructure.

Affected Products

• LambertGroup Responsive HTML5 Audio Player PRO With Playlist (lbg-audio2-html5)
• All versions from initial release through 3.5.8
• WordPress sites with the plugin installed and active

Discovery Timeline

• 2025-08-20 - CVE-2025-54056 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-54056

Vulnerability Analysis

The vulnerability resides in the request handling logic of the lbg-audio2-html5 plugin. The plugin reflects user-controlled input into rendered HTML responses without proper sanitization or output encoding. Attackers can inject JavaScript payloads through HTTP request parameters that the plugin echoes back into the page.

Exploitation requires user interaction. A target must click a crafted link or visit an attacker-controlled page that triggers the request. The scope is changed, meaning the injected script can affect resources beyond the vulnerable component itself, including the broader WordPress session context.

Root Cause

The root cause is missing input validation and output encoding when handling request parameters. The plugin treats untrusted input as safe HTML or JavaScript context data. Without escaping functions such as esc_html(), esc_attr(), or wp_kses(), attacker-supplied markup is rendered directly in the response body.

Attack Vector

The attack vector is network-based and unauthenticated. An attacker constructs a URL containing a malicious payload in a vulnerable parameter and delivers it through phishing emails, social media, or compromised sites. When a victim with an active WordPress session loads the URL, the injected script executes under the site's origin. The script can read cookies not marked HttpOnly, perform actions as the user, or pivot to administrator account takeover when the victim is privileged.

No verified public proof-of-concept code is currently available. See the Patchstack Vulnerability Report for additional technical context.

Detection Methods for CVE-2025-54056

Indicators of Compromise

• HTTP requests to plugin endpoints containing URL-encoded <script>, onerror=, onload=, or javascript: payloads in query parameters
• Web server access logs showing referrers from untrusted external domains targeting lbg-audio2-html5 paths
• Unexpected outbound requests from administrator browser sessions to unknown domains after clicking links
• New or modified WordPress administrator accounts following user-clicked phishing campaigns

Detection Strategies

• Inspect HTTP request logs for parameter values containing HTML tags, event handlers, or JavaScript scheme prefixes targeting plugin URLs
• Deploy a Web Application Firewall (WAF) with reflected XSS signature rules covering WordPress plugin parameters
• Enable Content Security Policy (CSP) reporting to capture script execution violations against allowed sources

Monitoring Recommendations

• Forward WordPress and reverse proxy logs to a centralized SIEM for correlation against XSS payload patterns
• Monitor authenticated administrator sessions for anomalous API calls, REST endpoint usage, or privilege changes
• Alert on plugin file modifications and on creation of new administrative users outside change windows

How to Mitigate CVE-2025-54056

Immediate Actions Required

• Identify all WordPress instances running the Responsive HTML5 Audio Player PRO With Playlist plugin at version 3.5.8 or earlier
• Deactivate the plugin until a vendor patch is verified and applied
• Rotate administrator passwords and invalidate active sessions if exploitation is suspected
• Review WordPress audit logs for unauthorized account creation or configuration changes

Patch Information

At the time of publication, the vendor advisory listed in the Patchstack Vulnerability Report indicates the issue affects versions through 3.5.8. Administrators should consult the LambertGroup CodeCanyon product page for the latest fixed release and apply it as soon as it becomes available.

Workarounds

• Deactivate and remove the lbg-audio2-html5 plugin until a patched version is installed
• Deploy WAF rules that block HTML tags and JavaScript event handlers in query parameters sent to the plugin
• Enforce a strict Content Security Policy that disallows inline scripts and restricts script sources to trusted origins
• Train administrators to avoid clicking unsolicited links to WordPress URLs containing unusual query parameters

# Example WAF rule (ModSecurity) blocking reflected XSS payloads to the plugin path
SecRule REQUEST_URI "@contains /wp-content/plugins/lbg-audio2-html5/" \
  "chain,deny,status:403,id:1054056,msg:'Block XSS payload targeting lbg-audio2-html5 (CVE-2025-54056)'"
  SecRule ARGS "@rx (?i)(<script|onerror=|onload=|javascript:)" "t:none,t:urlDecodeUni"