CVE-2026-103325 in TiendaCrypto para WooCommerce Plugin
Summary
by MITRE • 10/27/2026
The TiendaCrypto para WooCommerce WordPress plugin through 1.2.1 does not correctly verify the authenticity of its payment webhook, validating the request signature against a key that is always empty, which allows unauthenticated attackers to forge webhook notifications and mark arbitrary WooCommerce orders as paid on web servers that preserve request header case.
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Analysis
by VulDB Data Team • 10/27/2026
The vulnerability identified in TiendaCrypto para WooCommerce versions through 1.2.1 represents a critical authentication bypass rooted in improper verification of cryptographic signatures for payment webhook requests. This plugin, designed to facilitate cryptocurrency payments within the WordPress ecosystem via WooCommerce, relies on incoming HTTP POST requests from external payment gateways or blockchain explorers to confirm transaction completion. To ensure these notifications originate from legitimate sources and have not been tampered with during transit, the system is expected to validate a digital signature included in the request headers against a pre-shared secret key stored securely within the plugin configuration. However, due to a coding error, the implementation fails to retrieve or utilize this shared secret effectively. Instead of comparing the incoming signature against the actual configured API key, the validation logic compares it against an empty string or null value. This fundamental flaw renders the authentication mechanism entirely ineffective, as any arbitrary input will technically match an empty expected signature depending on how the comparison function is implemented in PHP, often resulting in a true evaluation for mismatched inputs if not strictly enforced with strict typing checks that are absent here.
From a technical perspective, this issue falls under CWE-287 Improper Authentication and CWE-345 Insufficient Verification of Data Authenticity. The core failure lies in the assumption that an empty key provides security or a bug where the variable holding the secret is never populated before use. In many PHP implementations, if the expected signature is null or empty string and the verification function does not explicitly reject such cases with strict equality checks (===), attackers can bypass this check entirely. This allows any actor on the internet to send crafted HTTP requests that mimic legitimate payment confirmations without possessing the private keys or credentials required by a secure system. The vulnerability specifically exploits web servers that preserve request header case, which is common in many Linux-based Apache and Nginx configurations unless explicitly modified via directives like ignore_case_header_names. This preservation allows attackers to manipulate specific headers used for signature transmission if they are not normalized correctly before comparison, although the primary issue remains the empty key validation itself regardless of header casing nuances.
The operational impact of this vulnerability is severe, enabling unauthenticated remote code execution in terms of business logic manipulation rather than server compromise. An attacker can forge webhook notifications to mark any WooCommerce order as paid without actually sending cryptocurrency or completing a real transaction. This leads directly to financial loss through the release of digital goods, services, or physical products before payment is received. Beyond direct monetary theft, this undermines trust in the e-commerce platform and exposes customer data associated with fraudulent orders. Attackers could also use this flaw to disrupt inventory management systems by artificially inflating sales figures or triggering automated workflows intended only for verified payments, such as shipping notifications or loyalty point allocations. The ability to arbitrarily alter order status constitutes a significant integrity violation that affects both the merchant's revenue and their operational reliability.
Mitigation strategies must address both immediate remediation and long-term security hygiene. The most effective solution is to upgrade TiendaCrypto para WooCommerce to version 1.2.2 or later, where developers have corrected the signature verification logic to properly retrieve and compare against the configured secret key using strict equality checks. Until an update is applied, administrators should consider disabling webhook-based payment confirmation methods if possible, relying instead on manual verification of blockchain transactions through block explorers before fulfilling orders. Additionally, implementing Web Application Firewall rules that restrict incoming POST requests from known legitimate IP ranges associated with major cryptocurrency gateways can provide a layer of defense in depth. It is also advisable to audit other plugins for similar patterns where cryptographic keys are mishandled or compared loosely against empty values. Regular security audits and adherence to OWASP guidelines for API authentication will help prevent such vulnerabilities in future deployments, ensuring that all external integrations maintain robust integrity checks before processing sensitive state changes within the application.