CVE-2026-62081 in Flexible PDF Coupons Plugin
Summary
by MITRE • 09/30/2026
Contributor Insecure Direct Object References (IDOR) in Flexible PDF Coupons <= 1.14.11 versions.
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Analysis
by VulDB Data Team • 09/30/2026
The vulnerability identified as an insecure direct object reference within the Flexible PDF Coupons plugin, specifically affecting versions up to and including 1.14.11, represents a critical authentication bypass mechanism that allows unauthorized users to access sensitive data or perform actions on behalf of other users. This flaw stems from the application's failure to implement proper authorization checks when processing requests related to coupon generation and management. In typical web applications using this plugin, PDF coupons are often generated dynamically based on user-specific parameters such as customer IDs, order numbers, or unique token identifiers passed directly in URL query strings or POST data without sufficient validation against the currently authenticated session's permissions.
From a technical perspective, the root cause lies in the lack of server-side verification that ensures the requesting user has explicit permission to access the specific object being requested. When an attacker manipulates these direct references by altering numerical IDs or alphanumeric tokens associated with coupon records, the application processes the request and returns the corresponding PDF document without verifying if the requester owns that data. This behavior aligns directly with CWE-639, which classifies insecure direct object references as a category of access control flaws where software provides direct access to objects based on user-supplied input. The absence of an intermediate authorization layer means that any authenticated user can iterate through sequential IDs or guess valid tokens to retrieve coupons belonging to other customers, potentially exposing personal information such as names, email addresses, and purchase history embedded within the generated PDFs.
The operational impact of this vulnerability is significant for both e-commerce businesses relying on the plugin and their end-users. Attackers with basic knowledge of web request manipulation can exploit this flaw using simple scripting tools to enumerate valid coupon IDs or target specific high-value customers by guessing sequential identifiers common in database implementations. This leads to a breach of confidentiality, as sensitive customer data is exposed without consent. Furthermore, if the coupons contain unique redemption codes that are tied to financial value or promotional discounts, attackers could potentially redeem these coupons for themselves or resell them, resulting in direct financial loss and inventory depletion for the merchant. The integrity of the coupon system is also compromised, as legitimate users may find their exclusive offers already redeemed by unauthorized parties.
This vulnerability maps closely to MITRE ATT&CK technique T1078, which covers valid accounts and specifically relates to improper authentication or authorization checks that allow lateral movement or data exfiltration within a trusted environment. It also reflects aspects of CWE-284 regarding Improper Access Control, where the system fails to restrict access to resources based on user roles or ownership. The exploitation does not require complex binary reverse engineering or remote code execution; instead, it relies on straightforward HTTP parameter tampering, making it highly accessible to a wide range of threat actors including automated bots and script kiddies scanning for known vulnerable plugins.
Mitigation strategies must focus on implementing robust authorization checks at the application logic level rather than relying solely on input validation. Developers should ensure that every request involving sensitive objects like PDF coupons verifies that the authenticated user's ID matches the owner ID stored in the database record before generating or serving the file. Implementing indirect object references, where users interact with opaque identifiers mapped to internal records via a secure session context, is recommended over exposing direct primary keys. Additionally, applying rate limiting and monitoring for unusual patterns of coupon access can help detect enumeration attempts. For administrators using versions 1.14.11 or earlier, immediate updating to the patched version released by the vendor is essential to resolve this security gap. Until an update is applied, restricting public-facing endpoints related to coupon generation and ensuring that all API calls require strict session validation are critical temporary countermeasures to prevent data leakage and financial fraud.