Description

The WP Hotel Booking WordPress plugin before 2.3.3 does not ensure that room quantities and the resulting order total are non-negative when placing a booking, and relies on client-controlled cart data, allowing unauthenticated users to create confirmed reservations for free or at an arbitrarily reduced price.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.3",
  "pubDate": "2026-08-06T22:16:47.567Z",
  "pubdate": "2026-08-06T22:16:47.567Z",
  "executiveSummary": "An input validation vulnerability exists in the WP Hotel Booking WordPress plugin prior to version 2.3.3, specifically related to the handling of room quantities and order total calculations during the booking process. The vulnerability stems from a lack of server-side validation ensuring that room quantities and the resulting financial totals are non-negative, combined with an insecure reliance on client-controlled cart data. This flaw empowers unauthenticated remote attackers to manipulate cart parameters directly on the client side, allowing them to create fully confirmed room reservations for free or at arbitrarily reduced prices.\nThe business impact of this vulnerability is significant, as it enables direct financial fraud, revenue loss, and inventory exhaustion through malicious bookings that bypass standard payment gateways. Because the flaw can be exploited by unauthenticated actors without elevated privileges, the attack surface is broad and accessible over the network via standard HTTP requests. Mitigation requires upgrading the WP Hotel Booking plugin to version 2.3.3 or later, where proper server-side sanitization and bounds checking for cart quantities and pricing are implemented.",
  "technicalDetails": "The root cause of this vulnerability lies in insufficient server-side input validation and business logic enforcement within the WP Hotel Booking plugin prior to version 2.3.3. Specifically, the application logic fails to verify that the quantity of rooms requested and the resulting calculated order total are non-negative integer values. Furthermore, the backend implementation relies entirely on client-controlled cart data transmitted during the reservation and checkout workflow without cryptographically signing or independently recalculating the line items and totals on the server.\nThe vulnerable component handles cart management and order placement processing within the plugin's booking routine. Because authentication is not required to interact with the initial booking and cart adjustment endpoints, unauthenticated threat actors can initiate a session, select target accommodations, and subsequently intercept or modify the HTTP requests responsible for submitting cart contents.\nThe step-by-step attack flow proceeds as follows: First, an unauthenticated attacker browses the target WordPress site utilizing the WP Hotel Booking plugin and initiates a standard room reservation. Second, the attacker captures the outgoing HTTP POST or AJAX request destined for the cart or checkout processing endpoint using an interception proxy. Third, the attacker manipulates the parameters corresponding to room quantities, inserting negative integers, zero values, or excessively discounted price parameters into the client-controlled cart data structure. Fourth, the server accepts the manipulated parameters without validating their logical constraints or cross-referencing them against authoritative database pricing. Finally, the backend processes the fraudulent transaction, applies the negative or reduced totals, and generates a successfully confirmed reservation record without requiring valid payment verification.\nThe post-exploitation impact includes unauthorized acquisition of service reservations, bypass of payment gateway logic, potential denial of service via artificial inventory depletion, and direct financial detriment to the site operator."
}