CVE-2026-101273 in Payments
Summary
by MITRE • 10/28/2026
Some of our API endpoints allowed to create order payments referencing a gift card by using the auto-incremented internal ID. This ID was not checked and allowed creating payments that reference gift cards from different organizers and thereby obtaining their secret. The gift card is not charged in this case, but by then triggering a refund on the payment, one can increase the value of the gift card.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 10/28/2026
The vulnerability described constitutes a critical business logic flaw rooted in insecure direct object references within an e-commerce or financial platform's API infrastructure. Specifically, the system exposes internal identifiers for gift cards through its order payment creation endpoints without implementing adequate authorization checks to verify that the requesting user possesses ownership rights over the referenced resource. This design oversight allows any authenticated user to supply arbitrary auto-incremented integer values as gift card IDs when initiating a payment transaction. Because the backend fails to validate whether the provided internal ID corresponds to a gift card issued by or associated with the current organizer, an attacker can successfully reference and access secret identifiers belonging to other organizers within the same ecosystem. This represents a classic instance of Insecure Direct Object Reference where sequential identification numbers are used as primary keys without sufficient access control mechanisms in place.
The operational impact of this vulnerability extends beyond simple data exposure due to the specific mechanics of how the gift card value is manipulated. Although the initial act of creating a payment referencing another organizer's gift card does not result in an immediate financial charge against that card, it establishes a transactional context that can be exploited further. By subsequently triggering a refund operation on this artificially created payment record, the attacker forces the system to reverse the transaction logic in a way that credits value back to the referenced gift card. This effectively allows for the unauthorized inflation of the gift card's balance using funds or credit mechanisms controlled by other organizers. The result is an arbitrary increase in asset value without corresponding legitimate commerce activity, leading to direct financial loss for the affected organizers and potential insolvency if exploited at scale.
From a threat modeling perspective aligned with industry standards, this vulnerability maps directly to CWE-284 Improper Access Control under the category of Insecure Direct Object References. The exploitation path leverages the lack of object-level authorization checks during both the creation and refund phases of the payment lifecycle. Furthermore, in terms of attack vectors defined by MITRE ATT&CK, this behavior aligns with T1530 Data from Information Repositories if viewed as unauthorized access to sensitive data (the secret ID), but more critically it falls under T1496 Resource Hijacking or potentially T1589 Gather Victim Identity Information depending on the initial reconnaissance phase. However, the core issue is a failure in business logic enforcement rather than a traditional software bug like buffer overflow or injection. The attacker exploits the trust placed in client-supplied identifiers to manipulate state and financial outcomes within the application's domain model.
Mitigation strategies must address both the immediate technical flaw and broader architectural principles regarding identifier management. First, all API endpoints handling sensitive resources such as gift cards must implement strict object-level authorization checks that verify the requesting user’s relationship with the specific resource instance before processing any request. This involves ensuring that every operation validates ownership or explicit permission rights against a secure session context rather than relying on the presence of an ID parameter alone. Second, it is highly recommended to replace auto-incremented integer identifiers with opaque, randomly generated unique identifiers such as UUIDs or ULIDs for sensitive entities like gift cards and payments. This approach prevents enumeration attacks where attackers guess sequential IDs to discover valid resources across different organizational boundaries. Additionally, implementing rate limiting on payment creation and refund endpoints can help mitigate bulk exploitation attempts while more permanent fixes are deployed. Finally, a comprehensive audit of all API endpoints should be conducted to identify similar patterns where internal identifiers are exposed or used without proper access control validation, ensuring that the principle of least privilege is enforced at every layer of the application stack.