CVE-2025-13603: WP AUDIO GALLERY Auth Bypass Vulnerability

CVE-2025-13603 Overview

The WP AUDIO GALLERY plugin for WordPress contains an Unauthorized Arbitrary File Read vulnerability affecting all versions up to and including 2.0. This security flaw stems from insufficient capability checks and the absence of nonce verification on the wpag_htaccess_callback function. The vulnerability enables authenticated attackers with subscriber-level access or higher to overwrite the site's .htaccess file with arbitrary content, potentially leading to arbitrary file read on the server under certain configurations.

Critical Impact

Authenticated attackers with minimal privileges (subscriber-level) can manipulate .htaccess files to read arbitrary files from the server, potentially exposing sensitive configuration data, database credentials, and other critical system files.

Affected Products

• WP AUDIO GALLERY plugin for WordPress versions 2.0 and earlier
• WordPress installations using vulnerable WP AUDIO GALLERY plugin versions
• Servers running Apache with .htaccess support enabled

Discovery Timeline

• 2026-02-19 - CVE CVE-2025-13603 published to NVD
• 2026-02-19 - Last updated in NVD database

Technical Details for CVE-2025-13603

Vulnerability Analysis

This vulnerability is classified under CWE-862 (Missing Authorization), which represents a critical security flaw where the application fails to perform proper access control checks before allowing sensitive operations. The vulnerable function wpag_htaccess_callback lacks two essential security mechanisms: capability verification to ensure the requesting user has appropriate permissions, and nonce validation to protect against cross-site request forgery attacks.

The attack can be executed remotely over the network and requires only low-privileged authentication (subscriber-level access), making it particularly dangerous in multi-user WordPress environments. Successful exploitation enables attackers to achieve unauthorized file access, potentially compromising confidential data stored on the server.

Root Cause

The root cause of this vulnerability lies in the improper implementation of authorization controls within the wpag_htaccess_callback function. The plugin developers failed to implement WordPress capability checks (such as current_user_can()) before allowing modification of the .htaccess file. Additionally, the absence of nonce verification using WordPress security functions like wp_verify_nonce() means the plugin cannot validate that requests originate from legitimate administrative actions.

This combination of missing security controls violates the principle of least privilege, allowing low-privileged users to perform actions that should be restricted to administrators only.

Attack Vector

The attack vector involves an authenticated user with minimal privileges (subscriber role) sending crafted requests to the vulnerable AJAX endpoint. The attacker can inject arbitrary directives into the .htaccess file, which Apache processes for access control and URL rewriting.

By manipulating the .htaccess file, an attacker can configure the server to expose sensitive files that would normally be protected. This could include:

• WordPress configuration files containing database credentials (wp-config.php)
• Plugin and theme source code
• Server-side logs and backup files
• Other restricted system files accessible to the web server process

The vulnerability is accessible through the WordPress AJAX handler without proper authorization gates, as documented in the plugin source code at util-functions.php and wp-audio-gallery.php.

Detection Methods for CVE-2025-13603

Indicators of Compromise

• Unexpected modifications to .htaccess files in the WordPress root or plugin directories
• Unusual AJAX requests to wpag_htaccess_callback endpoint from non-administrator accounts
• Server logs showing access to sensitive files that should be restricted (e.g., wp-config.php, backup files)
• New or suspicious subscriber-level accounts created on the WordPress site

Detection Strategies

• Monitor WordPress AJAX endpoints for requests to the wpag_htaccess_callback function from users without administrator privileges
• Implement file integrity monitoring on .htaccess files across all WordPress directories
• Review Apache access logs for patterns indicating arbitrary file read attempts
• Audit WordPress user accounts and permissions to identify potentially compromised subscriber accounts

Monitoring Recommendations

• Deploy a Web Application Firewall (WAF) with rules to detect and block .htaccess manipulation attempts
• Enable WordPress audit logging to track administrative actions and plugin function calls
• Configure alerts for changes to critical files including .htaccess, wp-config.php, and plugin configuration files
• Regularly review access logs for suspicious patterns targeting the WP AUDIO GALLERY plugin endpoints

How to Mitigate CVE-2025-13603

Immediate Actions Required

• Deactivate and remove the WP AUDIO GALLERY plugin until a patched version is available
• Review .htaccess files for unauthorized modifications and restore from known-good backups if necessary
• Audit subscriber and contributor accounts for suspicious activity or unauthorized creation
• Check server logs for evidence of exploitation attempts or successful file access

Patch Information

As of the last update, no official patch has been released for this vulnerability. The vulnerability affects WP AUDIO GALLERY versions 2.0 and earlier. Website administrators should monitor the Wordfence Vulnerability Report for updates on patch availability.

Until a fix is released, the recommended course of action is to completely remove the plugin from affected WordPress installations.

Workarounds

• Remove the WP AUDIO GALLERY plugin entirely if audio gallery functionality is not critical
• If the plugin must remain active, restrict user registration and limit subscriber-level account creation
• Implement server-level protections to prevent .htaccess modification via web requests
• Use WordPress security plugins to add additional capability checks and nonce verification for AJAX endpoints

# Protect .htaccess from web-based modifications
# Add to Apache configuration (httpd.conf or virtual host config)

<FilesMatch "^\.htaccess$">
    Require all denied
</FilesMatch>

# Alternatively, set file permissions to read-only
chmod 444 /var/www/html/.htaccess
chown root:root /var/www/html/.htaccess