SFTPGo is an open source, event-driven file transfer solution. From 2.2.0 until 2.7.3, the public web-client partial ZIP download endpoint for a browsable share validates client-supplied files entries with a raw byte-prefix comparison rather than a directory-boundary-aware check. An unauthenticated requester who can reach a public share can select a canonical path outside the shared directory when the target path begins with the shared directory's name, such as a sibling path that shares the same prefix. The endpoint then includes the out-of-scope file in the generated download, disclosing its contents. This issue is fixed in version 2.7.3.

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

## 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.