A directory traversal issue was discovered in OpenSlides before 4.2.5. Files can be uploaded to OpenSlides meetings and organized in folders. The interface allows users to download a ZIP archive that contains all files in a folder and its subfolders. If an attacker specifies the title of a file or folder as a relative or absolute path (e.g., ../../../etc/passwd), the ZIP archive generated for download converts that title into a path. Depending on the extraction tool used by the user, this might overwrite files locally outside of the chosen directory.