A research team from ETH Zurich found severe security vulnerabilities in several popular end-to-end encrypted (E2EE) cloud storage platforms, including Sync, pCloud, Icedrive, Seafile, and Tresorit. These vulnerabilities could allow attackers to inject files, tamper with data, or gain access to user files. The researchers notified the companies of their findings and, while some companies have promised to address the issues, others have not responded.