CVE-2025-40673 is a Missing Authorization vulnerability (CWE-862) affecting all versions of the DinoRANK product. DinoRANK is a software platform that presumably manages user invoices among other functionalities. The vulnerability arises because the application lacks proper access control checks on the endpoint '/facturas/YYYY-MM/SDRYYMM-XXXXX.pdf', which serves invoice PDF files. An attacker can exploit this by directly requesting invoice files belonging to any user without authentication or authorization verification. The filenames of these PDFs can be discovered through open-source intelligence (OSINT), insecure network traffic interception, or brute force guessing due to predictable naming conventions. The vulnerability is remotely exploitable over the network without requiring user interaction or prior authentication, as indicated by the CVSS vector (AV:N/AC:L/AT:N/PR:L/UI:N). The CVSS 4.0 base score is 5.3, categorizing it as a medium severity issue. The impact primarily concerns confidentiality, as unauthorized access to invoices can expose sensitive financial and personal data. There is no indication that integrity or availability are affected. No patches or fixes have been published yet, and no known exploits are currently in the wild. The vulnerability was assigned and published by INCIBE, a Spanish cybersecurity agency, suggesting regional awareness and involvement in its disclosure.

For European organizations using DinoRANK, this vulnerability poses a significant risk to the confidentiality of customer financial data. Unauthorized access to invoices can lead to exposure of personally identifiable information (PII), billing details, and transaction histories, which can be leveraged for identity theft, fraud, or targeted phishing attacks. This breach of privacy can also result in regulatory non-compliance, especially under the GDPR framework, leading to potential fines and reputational damage. Since DinoRANK is likely used by businesses managing client invoicing, the scale of impact depends on the number of users and invoices stored. The lack of authentication requirements means attackers can automate mass data harvesting. Although the vulnerability does not directly affect system integrity or availability, the indirect consequences through data leakage and loss of customer trust can be severe. European organizations must consider this a priority to prevent data breaches and maintain compliance with data protection laws.

Immediate mitigation should focus on implementing strict access control checks on the invoice retrieval endpoint to ensure that only authenticated and authorized users can access their own invoices. This includes validating the user's identity and verifying ownership of the requested invoice before serving the PDF file. Additionally, the application should avoid predictable or guessable file naming conventions; consider using randomized or tokenized filenames that are hard to enumerate. Employing HTTPS with strong encryption will prevent interception of filenames over the network. Organizations should monitor access logs for unusual or repeated access attempts to invoice files, which may indicate brute force or reconnaissance activity. Until an official patch is released, applying web application firewalls (WAFs) with rules to restrict direct access to invoice files or rate-limit requests can reduce exploitation risk. Finally, conducting a thorough audit of all endpoints for similar missing authorization issues is recommended to prevent analogous vulnerabilities.