CVE-2025-57921: Frontend File Manager Auth Bypass Flaw

CVE-2025-57921 Overview

CVE-2025-57921 is a Missing Authorization vulnerability [CWE-862] in the N-Media Frontend File Manager plugin (nmedia-user-file-uploader) for WordPress. The flaw affects all plugin versions up to and including 23.3. Attackers can exploit incorrectly configured access control security levels to reach functionality that should require authorization. The vulnerability is remotely exploitable over the network without authentication or user interaction. Successful exploitation impacts integrity of the affected WordPress site by allowing unauthorized actions through the plugin's file management interface.

Critical Impact
Unauthenticated attackers can reach protected plugin functionality due to missing authorization checks, enabling manipulation of file management operations on affected WordPress installations.

Affected Products

N-Media Frontend File Manager plugin (nmedia-user-file-uploader) for WordPress
All versions from n/a through 23.3
WordPress installations with the plugin activated

Discovery Timeline

2025-09-22 - CVE-2025-57921 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-57921

Vulnerability Analysis

The vulnerability is a Broken Access Control issue classified under [CWE-862] Missing Authorization. The N-Media Frontend File Manager plugin exposes plugin functionality without verifying that the requester holds the required capability or role. WordPress plugins commonly enforce authorization through current_user_can() checks, nonce validation, and role gating on AJAX or REST endpoints. When these checks are absent or improperly scoped, requests from unauthenticated users are processed as if they carried valid privileges.

The EPSS score of 0.299% suggests limited near-term exploitation probability, but the network-reachable, no-authentication attack profile increases exposure for public WordPress sites.

Root Cause

The root cause is an incorrectly configured access control security level on plugin actions handled by nmedia-user-file-uploader. Endpoints responsible for file operations do not consistently validate the caller's identity or capability before executing privileged logic. This design gap converts privileged file management actions into functionality reachable by anonymous HTTP requests.

Attack Vector

The attack vector is network-based and requires no authentication or user interaction. An attacker sends crafted HTTP requests to plugin endpoints exposed by a WordPress site running a vulnerable version. Because the requests bypass authorization enforcement, the plugin processes them and performs actions the attacker should not be permitted to trigger. The impact is limited to integrity, per the CVSS vector, meaning the attacker can modify data handled by the plugin without directly accessing confidential content or causing service disruption.

No verified public proof-of-concept code is referenced in the advisory. For technical details, see the Patchstack WordPress Vulnerability advisory.

Detection Methods for CVE-2025-57921

Indicators of Compromise

Unexpected files appearing in WordPress upload directories associated with the Frontend File Manager plugin
Anonymous HTTP POST requests targeting admin-ajax.php with plugin-specific actions from nmedia-user-file-uploader
Modifications to file metadata or plugin-managed records without a corresponding authenticated session
Access log entries showing requests to plugin endpoints from unauthenticated sources

Detection Strategies

Inventory WordPress sites and identify installations running nmedia-user-file-uploader at version 23.3 or earlier
Review web server access logs for requests to plugin AJAX or REST endpoints originating without a valid authentication cookie
Correlate file system changes in upload directories with WordPress audit logs to identify unauthenticated write activity
Deploy Web Application Firewall (WAF) rules that flag anonymous requests to plugin-specific actions

Monitoring Recommendations

Enable file integrity monitoring on WordPress upload paths and plugin directories
Alert on spikes in admin-ajax.php traffic targeting plugin actions from single source IPs
Track plugin version state across managed WordPress fleets to detect unpatched instances
Forward WordPress and web server logs to a centralized analytics platform for correlation

How to Mitigate CVE-2025-57921

Immediate Actions Required

Update the N-Media Frontend File Manager plugin to a version later than 23.3 once the vendor releases a fix
Temporarily deactivate the plugin on production sites if a patched version is not yet available
Restrict access to plugin endpoints at the WAF or reverse proxy layer until remediation is confirmed
Audit upload directories for unauthorized files and remove any that cannot be attributed to legitimate users

Patch Information

Refer to the Patchstack advisory for nmedia-user-file-uploader for the latest vendor patch status and fixed version guidance. Apply the updated plugin release through the WordPress plugin manager or WP-CLI once available.

Workarounds

Block unauthenticated requests to plugin AJAX and REST endpoints using WAF rules
Enforce IP allow-lists on wp-admin and admin-ajax.php where operationally feasible
Disable frontend file upload functionality until a patched plugin version is deployed
Require authentication at the reverse proxy for any URI path handled by the plugin

bash

# Example: disable the vulnerable plugin using WP-CLI
wp plugin deactivate nmedia-user-file-uploader
wp plugin status nmedia-user-file-uploader