Summary

A Broken Access Control vulnerability was disclosed in the Felan Framework WordPress plugin (versions up to and including 1.1.4). The plugin exposes a handler named process_plugin_actions that does not properly check user capabilities or verify nonces before performing plugin activation/deactivation. An attacker who can register or authenticate as a low-privilege user (subscriber or similar) may be able to trigger plugin activation/deactivation actions. This could allow a malicious actor to disable security plugins, enable malicious plugins, or otherwise change plugin state — increasing risk of site compromise. The issue is fixed in Felan Framework 1.1.5 (CVE-2025-10849).

What happened (high level)

The plugin provided a request handler (or action) that processes plugin activation/deactivation requests but omitted critical authorization checks (capability checks such as current_user_can('activate_plugins')) and nonce verification (check_admin_referer() / wp_verify_nonce()). As a result, any authenticated user with a low privilege level — typically a Subscriber-level account — can invoke actions that should be limited to administrators and effectively change which plugins are active on the site.

The maintainers released Felan Framework version 1.1.5 to correct the issue. The vulnerability is tracked as CVE-2025-10849 and has been assessed with a medium/low CVSS in some published assessments; practical risk hinges on whether the site allows registration or has low-privilege accounts that can be abused.

A technical look (what the vulnerability looks like)

Below are conceptual code snippets to explain the root cause without providing a direct exploit.

Vulnerable pattern (pseudo-code, simplified):

function process_plugin_actions() {
    $action = isset($_REQUEST['action_type']) ? $_REQUEST['action_type'] : '';
    $plugin = isset($_REQUEST['plugin']) ? $_REQUEST['plugin'] : '';

    if ($action === 'activate') {
        activate_plugin( $plugin );
    } elseif ($action === 'deactivate') {
        deactivate_plugins( $plugin );
    }
}
add_action( 'admin_post_process_plugin_actions', 'process_plugin_actions' );
add_action( 'admin_ajax_process_plugin_actions', 'process_plugin_actions' );

What’s missing:

• No capability check (e.g. current_user_can( 'activate_plugins' ))
• No nonce verification / CSRF protection (check_admin_referer() or wp_verify_nonce())
• The handler may be hooked into entry points reachable to authenticated users (admin-ajax.php or admin-post.php), making it callable by lower-level roles that can access those endpoints

Corrected pattern (safe approach):

function process_plugin_actions() {
    if ( ! current_user_can( 'activate_plugins' ) ) {
        wp_die( 'Insufficient privileges', 403 );
    }

    check_admin_referer( 'bulk-plugins' ); // or a dedicated nonce action

    $action = sanitize_text_field( $_REQUEST['action_type'] ?? '' );
    $plugin = sanitize_text_field( $_REQUEST['plugin'] ?? '' );

    if ( $action === 'activate' ) {
        activate_plugin( $plugin );
    } elseif ( $action === 'deactivate' ) {
        deactivate_plugins( $plugin );
    }
}

Bottom line: the missing authorization and nonce checks are the root cause. This maps to Broken Access Control (OWASP A05).

How exploitable is this? Practical attack vectors and constraints

Exploitability depends on several environmental factors:

1. User registration policy: If your site allows self-registration (Subscriber or similar), an attacker can create an account and attempt to call the vulnerable endpoint. Sites without open registration are less at risk.
2. Visibility of the handler: If the action is reachable via admin-ajax.php or admin-post.php from the front end, it is more convenient for the attacker.
3. Plugin availability on the site: Impact depends on which plugins are installed. Activating a malicious plugin or deactivating security plugins increases risk substantially.
4. Detection and response: With audit logging and monitoring, plugin state changes are visible and can be reverted. Without detection, attackers can act without time pressure.

Given these constraints, this vulnerability is practical on many WordPress setups — especially community sites, membership sites, or sites that allow registration.

Real impacts and scenarios to be concerned about

• An attacker registers as a Subscriber on a forum or blog, deactivates a security plugin and activates a dormant backdoor plugin (if present), leading to remote code execution.
• On agency-managed or multi-site environments, a low-priv user deactivates caching/security/maintenance plugins, causing downtime and client impact.
• An attacker activates a plugin with a known RCE vulnerability to chain further exploits.
• Even if no malicious plugin exists, deactivating monitoring plugins can blind owners to later intrusions.

Impact ranking (practical):

• Confidentiality: medium
• Integrity: medium-high
• Availability: medium
• Overall: environment dependent — low on locked-down sites, severe on community sites

Detection: what to look for in logs and the database

If you want to check whether someone tried to exploit this vulnerability or whether your site was modified, look for the following signals.

HTTP / Web server logs

• POST requests to:
  • /wp-admin/admin-ajax.php?action=process_plugin_actions
  • /wp-admin/admin-post.php?action=process_plugin_actions
• Requests that include parameters like plugin, action_type, _wpnonce (or lacking _wpnonce).
• Example sanitized log line:

  2025-10-16T12:22:11Z POST /wp-admin/admin-ajax.php?action=process_plugin_actions plugin=hello-dolly.php action_type=activate 200 "-" "Mozilla/5.0..."

WordPress activity and site logs

• Changes to the active_plugins option in wp_options with suspicious timestamps:

  SELECT option_value FROM wp_options WHERE option_name = 'active_plugins';

• Audit logs showing plugin activation/deactivation events by low-privilege usernames.

File system indicators

• New plugin directories under wp-content/plugins/ or modified plugin timestamps inconsistent with your updates.

User and session checks

• Unexpected user accounts or suspicious emails.
• Simultaneous logins or sessions for low-privilege users around plugin change times.

WP-CLI helpful commands

wp plugin list --status=active
wp plugin deactivate plugin-slug
ls -lt wp-content/plugins

Short-term mitigations (if you cannot immediately update)

The safest course is to update Felan Framework to 1.1.5 immediately. If you cannot update, consider the following temporary mitigations to reduce risk until you can patch:

1. Restrict access to the plugin action endpoint via WAF or firewall rules

   Block requests that call action=process_plugin_actions unless they originate from administrator IPs or authenticated admin sessions. Use your web application firewall, reverse proxy, or webserver access controls to enforce this.

2. Add a temporary mu-plugin that enforces capability checks

   Drop a must-use plugin (wp-content/mu-plugins/block-felan-actions.php) that denies unauthorized calls before the vulnerable plugin runs:

   <?php
   // mu-plugin: block-felan-actions.php
   add_action( 'admin_init', function() {
       $action = $_REQUEST['action'] ?? '';
       if ( $action === 'process_plugin_actions' ) {
           if ( ! is_user_logged_in() || ! current_user_can( 'activate_plugins' ) ) {
               wp_die( 'Unauthorized', 403 );
           }
       }
   } );

   This mu-plugin runs early and blocks calls until you can update.

3. Ensure capability boundaries are correct

   Verify only administrators have the activate_plugins capability. Check role-management or membership plugins for accidental privilege escalation.

4. Disable or restrict user registration

   If your site does not need open registration, disable it (Settings → General → Membership) or add verification to reduce fake account creation.

5. Restrict wp-admin access by IP

   Use webserver rules (nginx/apache) or reverse-proxy controls to limit access to /wp-admin and admin endpoints to trusted IP ranges where feasible.

Note: mu-plugin mitigation is practical for emergencies but should be replaced with the upstream patch as soon as possible.

Recovery steps if you suspect compromise

1. Isolate — Put the site in maintenance mode or take a snapshot to prevent further damage where possible.
2. Take a backup — Full backup (files + DB) to preserve evidence before making changes.
3. List active plugins — wp plugin list --status=active and note unexpected changes.
4. Inspect newly activated or unknown plugins — Check plugin folders for suspicious names, timestamps, or obfuscated PHP.
5. Deactivate and remove suspicious plugins — wp plugin deactivate suspicious-plugin and delete the folder if malicious.
6. Rotate credentials — Reset passwords for all admin and affected accounts; invalidate sessions (e.g., wp user session destroy <user-id>).
7. Search for persistence/backdoors — Scan for suspicious PHP files under wp-content, rogue cron entries, and unexpected active_plugins manipulations.
8. Scan with multiple tools — Use reputable malware scanners and file-integrity tools to identify common malicious patterns.
9. Restore from a clean backup if needed — If cleanup is difficult, restore a pre-compromise backup and then patch the plugin.
10. Forensics and monitoring — Review logs for attack vectors, dates, and involved accounts; increase logging sensitivity going forward.

Hardening and longer-term defenses

This incident highlights broader hygiene items. Consider the following permanent measures:

• Keep WordPress core, themes and plugins updated. Use staging to validate updates before production.
• Minimize plugins; remove unused extensions.
• Restrict user registration or apply stricter onboarding and verification.
• Enforce least privilege; regularly audit roles and capabilities.
• Use strong admin authentication: unique admin usernames, strong passwords, and two-factor authentication for privileged accounts.
• Enable audit logging for plugin activation/deactivation and user role changes.
• Implement file-integrity monitoring for wp-content/plugins/ and other critical paths.
• Restrict access to /wp-admin and admin-ajax endpoints by IP or other network controls where feasible.
• Regularly review user accounts and remove or demote stale users.

Layered protection approach (non-vendor)

Adopt a defence-in-depth strategy combining prevention, detection and response:

• Prevention: Patch management, least privilege, network access controls, and input validation.
• Detection: Audit logs, file-integrity monitoring, and webserver request logging tuned to detect suspicious admin-ajax/admin-post requests.
• Response: Playbooks for isolating an incident, backup and restore procedures, and post-incident forensic processes.

Where a Web Application Firewall or reverse proxy is available, use it to create targeted rules (virtual patches) to block exploitation attempts until patches are applied. This should be treated as a temporary mitigation, not a substitute for updating the plugin.

Suggested WAF rule concepts (high level)

Below are conceptual enforcement strategies suitable for a WAF, mod_security, nginx rules, or reverse-proxy filters. These are high-level and safe — intended to reduce risk without producing exploitable signatures.

• Block or require admin authentication for requests where:
  • REQUEST_URI contains admin-ajax.php or admin-post.php, and
  • REQUEST contains action=process_plugin_actions, and
  • Caller is not an authenticated administrator session.
• Deny plugin activation/deactivation POSTs that either:
  • Lack a valid WP nonce parameter, or
  • Are performed by a user role that does not have activate_plugins.
• Rate-limit or block repeated attempts from the same IP to call plugin management endpoints.

Conceptual ModSecurity-style pseudo-rule (illustrative only):

SecRule REQUEST_URI "@contains admin-ajax.php" "phase:2,chain,deny,log,msg:'Block plugin action from non-admin'"
SecRule ARGS:action "@contains process_plugin_actions" "chain"
SecRule &REQUEST_HEADERS:Cookie "!@gt 0" "id:9999,deny"

Tune any rules carefully to avoid false positives and maintain access for legitimate administrators.

Appendix: useful WP-CLI and SQL checks

• Check active plugins (WP-CLI):

  wp plugin list --status=active

• Force deactivate all plugins (use with caution):

  wp plugin deactivate --all

• Inspect active_plugins option (SQL):

  SELECT option_value FROM wp_options WHERE option_name = 'active_plugins';

• Find recently modified plugin files (Linux shell):

  find wp-content/plugins -type f -mtime -7 -ls

• Search for suspicious code patterns:

  grep -R --line-number "eval(" wp-content/plugins/
  grep -R --line-number "base64_decode(" wp-content/

• List users with roles and last login times (if audit plugin installed):

  wp user list --fields=ID,user_login,user_email,roles,last_login

Final recommendations (concise checklist)

1. Update Felan Framework to 1.1.5 immediately.
2. If you cannot update immediately:
   • Deploy the mu-plugin mitigation shown above, or
   • Use your WAF/firewall to apply a temporary virtual patch that blocks process_plugin_actions from non-admin users.
3. Scan for signs of compromise (active plugins, unexpected files, logs).
4. Rotate credentials for admin accounts and review all user roles.
5. Implement hardening measures described above (2FA, limit registration, audit logging).
6. Maintain incident response procedures and monitoring to reduce dwell time for attackers.