CVE-2025-48246

Executive Summary

CVE-2025-48246 is a Missing Authorization vulnerability in the WordPress ecosystem, specifically affecting the The Events Calendar plugin by StellarWP. This flaw allows an authenticated attacker (with low privileges) to exploit incorrectly configured access control security levels, potentially leading to unauthorized access to sensitive event data or the ability to modify event settings. The vulnerability affects all versions up to and including 6.11.2.1. As of this report, no official patch has been released, and no public proof-of-concept (PoC) or exploit code is available. The EPSS score is 0.0%, indicating low exploitation activity in the wild, but the risk remains for unpatched installations.

Supply Chain & Package Security

This vulnerability is specific to the WordPress plugin ecosystem. The plugin is distributed via the official WordPress plugin repository and can be installed directly from the WordPress admin dashboard. Organizations should verify the integrity of the plugin files by checking checksums provided by the vendor or WordPress.org. No known supply chain compromise has been reported for this CVE.

CVSS Breakdown & Threat Level

• CVSS Score: 5.4 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
• Attack Vector (AV): Network – The vulnerability can be exploited remotely.
• Attack Complexity (AC): Low – No special conditions are required.
• Privileges Required (PR): Low – An attacker needs a valid WordPress user account (e.g., subscriber).
• User Interaction (UI): None – No user action is required.
• Scope (S): Unchanged – The exploit does not affect other components.
• Confidentiality (C): Low – Limited unauthorized data access.
• Integrity (I): Low – Limited unauthorized modification.
• Availability (A): None – No impact on system availability.

Threat Level: Medium. The vulnerability requires authentication, but low-privileged users can exploit it. The lack of a patch and the widespread use of The Events Calendar plugin increase the risk for unpatched sites.

Deep Dive & Mechanics

The vulnerability resides in the The Events Calendar plugin's access control mechanisms. The plugin fails to properly validate user permissions when processing certain AJAX requests or REST API endpoints related to event management. Specifically, the missing authorization flaw allows a user with minimal privileges (e.g., subscriber) to perform actions that should be restricted to higher-privileged roles (e.g., editor or administrator).

Root Cause: The plugin uses current_user_can() checks inconsistently or with incorrect capability names. In some code paths, the check is missing entirely, allowing unauthorized access to functions like wp_ajax_* handlers or REST routes.

Attack Vector: An authenticated attacker can craft a malicious HTTP request to a vulnerable endpoint, bypassing the intended access controls. For example, they might be able to:

• View private or draft events.
• Modify event metadata (e.g., change event dates, descriptions).
• Delete events created by other users.

Impact: Successful exploitation could lead to data leakage (confidentiality) and unauthorized data modification (integrity). In a multi-tenant WordPress environment (e.g., WordPress Multisite), the impact could be more severe.

Vulnerable vs. Patched Code

Since no official patch is available, the following is a hypothetical comparison based on common missing authorization patterns.

Vulnerable Code (Example):

// In a vulnerable version, the AJAX handler lacks permission check
add_action('wp_ajax_update_event', 'handle_update_event');
function handle_update_event() {
    // No current_user_can() check
    $event_id = $_POST['event_id'];
    update_post_meta($event_id, '_EventStartDate', $_POST['start_date']);
    wp_send_json_success();
}

Patched Code (Expected):

add_action('wp_ajax_update_event', 'handle_update_event');
function handle_update_event() {
    // Proper capability check
    if (!current_user_can('edit_others_posts')) {
        wp_send_json_error('Insufficient permissions');
        return;
    }
    $event_id = $_POST['event_id'];
    update_post_meta($event_id, '_EventStartDate', $_POST['start_date']);
    wp_send_json_success();
}

Key Difference: The patched version adds a current_user_can('edit_others_posts') check before processing the request.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress site running The Events Calendar <= 6.11.2.1.
• A valid low-privileged user account (e.g., subscriber).

Exploitation Steps:

1. Log in as the low-privileged user.
2. Identify vulnerable endpoints by analyzing the plugin's JavaScript or REST API routes. Common endpoints include:
   • /wp-admin/admin-ajax.php?action=the-events-calendar-*
   • /wp-json/tribe/events/v1/*
3. Craft a request to modify an event. Example using curl:

   curl -X POST \
     -c cookies.txt -b cookies.txt \
     -d "action=tribe_events_update&event_id=123&start_date=2025-06-01" \
     https://target.com/wp-admin/admin-ajax.php
   

4. If successful, the event will be modified without proper authorization.

Note: No public exploit code is available. The above is a generic example.

Blue Team (Detection & Defense)

Detection:

• Monitor for unusual AJAX requests from low-privileged users to sensitive endpoints.
• Look for patterns like action=tribe_events_* in logs.
• Use the Sigma rule below to detect unauthorized access attempts.

Defense:

• Apply the principle of least privilege: ensure users have only the roles they need.
• Use a Web Application Firewall (WAF) to block suspicious requests.
• Monitor for failed permission checks in WordPress debug logs.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests to /wp-admin/admin-ajax.php with action parameters containing tribe_events_* from low-privileged users.
  • Unusual REST API calls to /wp-json/tribe/events/v1/ with PUT or POST methods from non-admin users.

• File IOCs:

  • Modified event posts in the database where post_author does not match the expected user.
  • Unexpected changes to _EventStartDate, _EventEndDate, or _EventVenueID meta keys.

• Log IOCs:

  • WordPress debug log entries showing current_user_can() failures for edit_others_posts or manage_options.

Detection Engineering

YARA Rule

rule Detect_CVE_2025_48246_Missing_Auth {
    meta:
        description = "Detects missing authorization patterns in The Events Calendar plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-48246"
    strings:
        $vuln_func = "wp_ajax_" nocase
        $missing_check = "current_user_can" nocase
        $plugin_path = "the-events-calendar" nocase
    condition:
        $plugin_path and $vuln_func and not $missing_check
}

Sigma Rule

title: CVE-2025-48246 - Missing Authorization in The Events Calendar
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects unauthorized AJAX requests to The Events Calendar endpoints
author: Valters IT
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-uri-query|contains: 'action=tribe_events_'
        cs-method: 'POST'
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate admin actions
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-48246 - The Events Calendar Missing Authorization Attempt";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/wp-admin/admin-ajax.php"; http_uri;
    content:"action=tribe_events_"; http_client_body;
    classtype:attempted-recon;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin if it is not critical to operations until a patch is released.
2. Restrict user roles – Remove unnecessary low-privileged accounts.
3. Apply a virtual patch using a WAF to block requests to vulnerable endpoints from non-admin users.

Long-term Fix:

• Monitor the StellarWP changelog for a patched version (expected > 6.11.2.1).
• Once available, update the plugin immediately.
• Conduct a security audit of all WordPress plugins for similar missing authorization issues.

Workaround:

• Use a WordPress security plugin (e.g., Wordfence) to add additional access control layers.
• Implement custom code to add current_user_can() checks to all AJAX handlers.

Valters IT
Securing Digital Frontiers