Magento versions 2.4.2 (and earlier), 2.4.1-p1 (and earlier) and 2.3.6-p1 (and earlier) are affected by a Violation of Secure Design Principles vulnerability in RMA PDF filename formats. Successful exploitation could allow an attacker to get unauthorized access to restricted resources.
https://github.com/advisories/GHSA-7gh6-f4jh-3crq
https://helpx.adobe.com/security/products/magento/apsb21-30.html