CVE-2025-10749: Azure Storage WordPress Plugin Auth Bypass

CVE-2025-10749 Overview

CVE-2025-10749 affects the Microsoft Azure Storage for WordPress plugin in all versions up to and including 4.5.1. The plugin fails to enforce capability checks on the azure-storage-media-replace AJAX action. Authenticated users with subscriber-level access or higher can delete arbitrary media files from the WordPress Media Library through the replace_attachment parameter. Exploitation requires access to a nonce that the plugin exposes to all authenticated users. The issue is tracked under [CWE-862] Missing Authorization.

Critical Impact

Any authenticated WordPress user, including low-privilege subscribers, can delete arbitrary media files from the site's Media Library, causing content loss and site defacement.

Affected Products

• Microsoft Azure Storage for WordPress plugin — all versions through 4.5.1
• WordPress installations using the windows-azure-storage plugin
• Any site allowing subscriber-level or higher user registration with the vulnerable plugin active

Discovery Timeline

• 2025-10-24 - CVE-2025-10749 published to NVD
• 2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-10749

Vulnerability Analysis

The vulnerability resides in the class-windows-azure-replace-media.php file of the Microsoft Azure Storage for WordPress plugin. The plugin registers an AJAX action named azure-storage-media-replace that handles media replacement operations. The handler validates a nonce but does not confirm that the requesting user has the appropriate capability, such as delete_post or upload_files, for the target attachment.

Because WordPress exposes the required nonce to any logged-in user, the missing capability check allows subscribers to invoke the action with a replace_attachment parameter referencing any attachment ID. The handler proceeds to delete the referenced media object.

This produces integrity and availability impact on site content. Attackers can remove images, documents, and other assets referenced by posts and pages. Deleted files break front-end presentation and can disrupt e-commerce catalogs, documentation portals, and media-heavy publications.

Root Cause

The root cause is a missing authorization check [CWE-862] in the AJAX handler. The plugin authenticates the request through nonce verification but does not call current_user_can() against the target attachment before performing the delete operation. Nonce verification alone confirms request intent, not user privilege.

Attack Vector

An attacker registers or authenticates as a subscriber-level user. The attacker retrieves the nonce exposed by the plugin, then issues a POST request to admin-ajax.php with action=azure-storage-media-replace and a replace_attachment value corresponding to the target attachment ID. The server processes the request and deletes the referenced media without verifying privilege.

Refer to the plugin source at class-windows-azure-replace-media.php line 152 and line 346 for the vulnerable handler implementation.

Detection Methods for CVE-2025-10749

Indicators of Compromise

• POST requests to /wp-admin/admin-ajax.php containing action=azure-storage-media-replace originating from low-privilege user sessions
• Unexpected attachment_deleted or deleted_post events in WordPress logs for attachment post types
• Missing media files referenced by published posts and pages
• Requests to the AJAX endpoint from subscriber accounts that do not typically interact with the Media Library

Detection Strategies

• Enable WordPress action logging for delete_attachment and correlate with the requesting user's role
• Inspect web server access logs for admin-ajax.php calls with the azure-storage-media-replace action parameter
• Alert on media deletion events performed by users below editor level
• Monitor for bursts of attachment deletions within short time windows

Monitoring Recommendations

• Ingest WordPress and web server logs into a centralized platform for correlation of AJAX activity with user roles
• Baseline normal Media Library activity and flag deviations, particularly deletions from subscriber accounts
• Track plugin file integrity to confirm the patched version of windows-azure-storage is deployed across sites

How to Mitigate CVE-2025-10749

Immediate Actions Required

• Update the Microsoft Azure Storage for WordPress plugin to a version later than 4.5.1 as soon as the vendor publishes a fix
• Audit user accounts and remove unnecessary subscriber-level registrations
• Disable open user registration on sites that do not require it by unchecking Settings → General → Membership
• Review recent Media Library activity for unauthorized deletions and restore from backup where needed

Patch Information

Refer to the WordPress plugin changeset for the vendor's remediation commit. The Wordfence Vulnerability Report tracks fixed version availability and additional remediation guidance.

Workarounds

• Deactivate the Microsoft Azure Storage for WordPress plugin until a patched release is installed
• Restrict access to /wp-admin/admin-ajax.php for the azure-storage-media-replace action via a web application firewall rule
• Enforce role hardening so that subscriber accounts cannot reach admin AJAX endpoints unrelated to their function
• Maintain off-site backups of the wp-content/uploads directory and the WordPress database to enable rapid recovery

# Example WAF rule concept blocking the vulnerable AJAX action for non-editor roles
# ModSecurity pseudo-rule
SecRule REQUEST_URI "@endsWith /wp-admin/admin-ajax.php" \
  "chain,phase:2,deny,status:403,id:1010749,msg:'Block CVE-2025-10749 AJAX action'"
  SecRule ARGS:action "@streq azure-storage-media-replace" \
    "chain"
    SecRule REQUEST_COOKIES:/wordpress_logged_in_/ "@rx .*"