Cockpit-files: cockpit-files: arbitrary file ownership change via symlink following in privileged paste

A flaw was found in cockpit-files. A low-privileged local user can exploit this vulnerability by crafting a directory containing a symbolic link (symlink) and then using the privileged "Paste as owner" function. This allows for arbitrary file ownership changes outside the intended pasted directory, leading to a compromise of data integrity. In some cases, this could also lead to reduced confidentiality if the new ownership grants unauthorized read access. Exploitation requires user interaction to select a non-original owner during the paste operation.