SFTPGo is an open source, event-driven file transfer solution. From 2.5.0 until 2.7.6, an authenticated user with copy permission can copy a source file denied by denied_patterns or outside allowed_patterns to an allowed destination name because file-pattern filters are evaluated only on the destination. The user can then read the denied file contents. Recursive directory copies can reproduce restricted contents under an allowed path, and the hide policy is bypassed because files that appear missing to stat and directory listings can still be copied. Home-directory boundaries, virtual-folder layout, per-directory permissions, access to other accounts, and administrative authorization remain enforced. This issue is fixed in 2.7.6.

Affected: Go: github.com/drakkan/sftpgo/v2

### Summary

File pattern filters (`denied_patterns` / `allowed_patterns`) were evaluated on the destination of a copy only. A user holding the copy permission could copy a file denied by the filters to a permitted name and then read it. A recursive directory copy reproduced the contents of a restricted directory under a path where the filters do not deny them, and the hide policy was affected in the same way: a file reported as missing by stat and by directory listings could still be copied.

### Details

An authenticated user can read the contents of files that the file pattern filters are configured to deny them. Nothing else is bypassed: the home directory, the virtual folder layout and the per-directory permissions are all still enforced, and both ends of the copy are paths the account can already reach. No access to other accounts and no administrative capability.