Tunnelier 4.30

- Implemented workaround for Ipswitch WS_FTP Server 7. Decreased the SSH maximum incoming packet size from 35 kB to 34 kB, which appears to avoid triggering a bug in WS_FTP Server 7 which would otherwise result in disconnect due to a MAC check failure. Warning: In our testing, WS_FTP Server 7 appeared to be highly susceptible to variations in the client's maximum incoming packet size. Observed symptoms included the server apparently entering an infinite loop and not responding to connections. It is our suspicion that, with high incoming packet sizes, the server incorrectly overwrites not only its buffers, but possibly also parts of its code. We suspect that this may indicate exploitable issues in WS_FTP Server 7. We have observed that it is possible for an authenticated client to mount at least a denial-of-service attack through a large maximum incoming packet size.
- FTP-to-SFTP bridge: Resolved compatibility issue with Windows File Explorer, Firefox, and possibly other FTP clients when the SFTP listing sent by the SFTP server lacks the modification time attribute. This can happen when listing drives with WinSSHD 5. The FTP-to-SFTP bridge will now provide the FTP client with a dummy modification time attribute in this case.