CVE-2025-49377

Executive Summary

CVE-2025-49377 is a Missing Authorization vulnerability in the Themefic Hydra Booking WordPress plugin, affecting versions from n/a through 1.1.9. This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized data access, modification, or privilege escalation within the WordPress ecosystem. The vulnerability is classified as a WordPress plugin issue and does not involve Apache or Nginx server software. No public proof-of-concept (PoC) or patch is currently available, and the EPSS score is 0.0%, indicating low exploitation likelihood at this time.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users are advised to monitor for updates from Themefic and apply patches as soon as they become available. Since the plugin is not an NPM, PyPI, Go, or Ruby package, no additional supply chain analysis is required.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
• Base Score: 6.3 (Medium)
• Attack Vector: Network (AV:N) – Exploitable remotely.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: None (PR:N) – No authentication needed.
• User Interaction: None (UI:N) – No user action required.
• Scope: Unchanged (S:U) – Impact confined to the vulnerable component.
• Confidentiality Impact: Low (C:L) – Limited data exposure.
• Integrity Impact: Low (I:L) – Limited data modification.
• Availability Impact: Low (A:L) – Limited service disruption.

Threat Level: Medium. While the CVSS score is moderate, the lack of required privileges and network exploitability increases the risk for unpatched installations.

Deep Dive & Mechanics

The vulnerability resides in the Hydra Booking plugin’s access control mechanisms. The plugin fails to properly validate user permissions when processing certain REST API endpoints or administrative actions. Specifically, the hydra-booking component does not enforce authorization checks for functions that should be restricted to authenticated users with specific roles (e.g., administrators or shop managers).

Root Cause: The plugin uses wp_ajax_* hooks or REST API routes without verifying the current_user_can() capability. This allows any unauthenticated visitor to trigger privileged actions, such as:

• Viewing or modifying booking data.
• Accessing configuration settings.
• Escalating privileges by creating new admin users (if such functionality is exposed).

Attack Vector: An attacker sends crafted HTTP requests to the vulnerable endpoints, bypassing authentication checks. For example:

POST /wp-admin/admin-ajax.php?action=hydra_booking_export

or

GET /wp-json/hydra-booking/v1/settings

Impact: Successful exploitation could lead to data breaches, unauthorized booking modifications, or full site compromise if combined with other vulnerabilities.

Vulnerable vs. Patched Code

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

Vulnerable Code (hydra-booking.php):

add_action('wp_ajax_nopriv_hydra_booking_export', 'hydra_booking_export_handler');
function hydra_booking_export_handler() {
    // No capability check
    $data = get_all_bookings();
    echo json_encode($data);
    wp_die();
}

Patched Code (hypothetical):

add_action('wp_ajax_hydra_booking_export', 'hydra_booking_export_handler');
function hydra_booking_export_handler() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized', 403);
    }
    $data = get_all_bookings();
    echo json_encode($data);
    wp_die();
}

The patch removes the nopriv_ prefix (which allows unauthenticated access) and adds a capability check using current_user_can().

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A WordPress site with Hydra Booking <= 1.1.9 installed and activated.
• Network access to the target.

Exploitation Steps:

1. Identify vulnerable endpoints by analyzing the plugin’s source code or using fuzzing tools.
2. Send a crafted request to trigger unauthorized access:

   curl -X POST "http://target/wp-admin/admin-ajax.php" \
        -d "action=hydra_booking_export"
   

3. If successful, the response will contain sensitive booking data.

Note: No public exploit code is available; this is a conceptual demonstration.

Blue Team (Defensive)

Detection:

• Monitor for requests to admin-ajax.php with suspicious action parameters (e.g., hydra_booking_*) from unauthenticated sources.
• Look for unusual patterns in REST API calls to /wp-json/hydra-booking/*.

Hunting:

• Search logs for HTTP 200 responses to admin-ajax.php without prior authentication.
• Use the Sigma rule below to detect exploitation attempts.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /wp-admin/admin-ajax.php with action=hydra_booking_* parameters.
  • REST API calls to /wp-json/hydra-booking/v1/* without valid authentication tokens.
• File IOCs:
  • Modified plugin files (e.g., hydra-booking.php) with unauthorized changes.
  • Unexpected files in /wp-content/uploads/ related to booking exports.
• Log IOCs:
  • Repeated 403 errors followed by 200 success for the same endpoint.
  • User creation events from unknown IPs (if privilege escalation is possible).

Detection Engineering

YARA Rule

rule CVE_2025_49377_Hydra_Booking_Missing_Auth {
    meta:
        description = "Detects missing authorization in Hydra Booking plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-49377"
    strings:
        $vuln_func = "wp_ajax_nopriv_hydra_booking" nocase
        $vuln_rest = "hydra-booking/v1" nocase
    condition:
        any of them
}

Sigma Rule

title: CVE-2025-49377 - Hydra Booking Missing Authorization
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated access to Hydra Booking plugin endpoints
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'action=hydra_booking'
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate admin actions (rare)
level: high

Suricata Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2025-49377 - Hydra Booking Missing Authorization Attempt";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"admin-ajax.php"; http_uri;
    content:"action=hydra_booking"; http_client_body;
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released by Themefic.
2. Implement a Web Application Firewall (WAF) rule to block requests to admin-ajax.php with action=hydra_booking* from unauthenticated sources.
3. Restrict access to /wp-admin/ using IP whitelisting or VPN.

Long-term Fix:

• Apply the official patch from Themefic once available.
• Conduct a security audit of all WordPress plugins for similar missing authorization issues.

Workaround:

• Add the following code to the theme’s functions.php to block unauthenticated access:

add_action('init', function() {
    if (defined('DOING_AJAX') && DOING_AJAX && !is_user_logged_in()) {
        $blocked_actions = ['hydra_booking_export', 'hydra_booking_import'];
        if (isset($_POST['action']) && in_array($_POST['action'], $blocked_actions)) {
            wp_die('Unauthorized', 403);
        }
    }
});

Valters IT
Securing Digital Frontiers