SFTPGo has path confinement bypass in public browsable share partial ZIP download

Summary

The public web-client endpoint for partial ZIP downloads of a browsable share did not correctly confine the client-supplied files entries to the shared directory. A requester able to reach a public share could read files located outside the shared directory, as long as the target's canonical path begins with the shared directory's name.

Patches

Fixed in v2.7.3. The fix replaces the raw prefix check with a directory-boundary–aware check.