A packet with illegal or unsupported version was received.

[drawntogether]

My client seems to be having trouble connecting. I can use windows command, WinSCP, FileZilla, pretty much any basic ftp client and I can connect in with no issues. They are using secureblackbox and I want to rule out there being any issue on my end that would be causing them connection issues?

Code: Select all

2024-04-03T20:35:19.741Z DI [FTP Session 8 xx.xx.xx.xx] Session 0x218cf2e21c0 with ID 8 created.
2024-04-03T20:35:19.741Z << [FTP Session 8 xx.xx.xx.xx] 220-FileZilla Server 1.8.1
2024-04-03T20:35:19.741Z << [FTP Session 8 xx.xx.xx.xx] 220 Please visit https://filezilla-project.org/
2024-04-03T20:35:19.778Z >> [FTP Session 8 xx.xx.xx.xx] AUTH TLS
2024-04-03T20:35:19.778Z DD [FTP Session 8 xx.xx.xx.xx] securer(1) ENTERING state = 0
2024-04-03T20:35:19.778Z DD [FTP Session 8 xx.xx.xx.xx] calling tls_layer_->set_certificate_file("C:\ProgramData\filezilla-server\certificates\2e16e8e5588853ed3159015d0790de3c245a9fc74eb035e90b6dd523210997ea\key.pem", "C:\ProgramData\filezilla-server\certificates\2e16e8e5588853ed3159015d0790de3c245a9fc74eb035e90b6dd523210997ea\cert.pem", "****")
2024-04-03T20:35:19.781Z DD [FTP Session 8 xx.xx.xx.xx] securer(1) EXITING state = 1
2024-04-03T20:35:19.781Z << [FTP Session 8 xx.xx.xx.xx] 234 Using authentication type TLS.
2024-04-03T20:35:19.781Z DD [FTP Session 8 xx.xx.xx.xx] ~securer(1) ENTERING state = 1
2024-04-03T20:35:19.781Z DD [FTP Session 8 xx.xx.xx.xx] calling tls_layer_->set_alpn()
2024-04-03T20:35:19.781Z DV [FTP Session 8 xx.xx.xx.xx] tls_layer_impl::server_handshake()
2024-04-03T20:35:19.781Z DV [FTP Session 8 xx.xx.xx.xx] tls_layer_impl::continue_handshake()
2024-04-03T20:35:19.781Z DD [FTP Session 8 xx.xx.xx.xx] ~securer(1) EXITING state = 2
2024-04-03T20:35:19.781Z DD [FTP Session 8 xx.xx.xx.xx] tls_layer_impl::on_send()
2024-04-03T20:35:19.781Z DV [FTP Session 8 xx.xx.xx.xx] tls_layer_impl::continue_handshake()
2024-04-03T20:35:19.836Z DD [FTP Session 8 xx.xx.xx.xx] tls_layer_impl::on_read()
2024-04-03T20:35:19.837Z DV [FTP Session 8 xx.xx.xx.xx] tls_layer_impl::continue_handshake()
2024-04-03T20:35:19.837Z DD [FTP Session 8 xx.xx.xx.xx] TLS handshakep: Received CLIENT HELLO
2024-04-03T20:35:19.837Z DD [FTP Session 8 xx.xx.xx.xx] tls_layer_impl::failure(-8)
2024-04-03T20:35:19.837Z !! [FTP Session 8 xx.xx.xx.xx] GnuTLS error -8: A packet with illegal or unsupported version was received.
2024-04-03T20:35:19.837Z !! [FTP Session 8 xx.xx.xx.xx] Control channel closed with error from source 0. Reason: ECONNABORTED - Connection aborted.
2024-04-03T20:35:19.837Z DI [FTP Session 8 xx.xx.xx.xx] Session 0x218cf2e21c0 with ID 8 destroyed.
2024-04-03T20:36:18.173Z DI [FTP Session 9 xx.xx.xx.xx] Session 0x218cf2e21c0 with ID 9 created.
2024-04-03T20:36:18.173Z << [FTP Session 9 xx.xx.xx.xx] 220-FileZilla Server 1.8.1
2024-04-03T20:36:18.173Z << [FTP Session 9 xx.xx.xx.xx] 220 Please visit https://filezilla-project.org/
2024-04-03T20:36:18.216Z >> [FTP Session 9 xx.xx.xx.xx] AUTH TLS
2024-04-03T20:36:18.216Z DD [FTP Session 9 xx.xx.xx.xx] securer(1) ENTERING state = 0
2024-04-03T20:36:18.216Z DD [FTP Session 9 xx.xx.xx.xx] calling tls_layer_->set_certificate_file("C:\ProgramData\filezilla-server\certificates\2e16e8e5588853ed3159015d0790de3c245a9fc74eb035e90b6dd523210997ea\key.pem", "C:\ProgramData\filezilla-server\certificates\2e16e8e5588853ed3159015d0790de3c245a9fc74eb035e90b6dd523210997ea\cert.pem", "****")
2024-04-03T20:36:18.220Z DD [FTP Session 9 xx.xx.xx.xx] securer(1) EXITING state = 1
2024-04-03T20:36:18.220Z << [FTP Session 9 xx.xx.xx.xx] 234 Using authentication type TLS.
2024-04-03T20:36:18.220Z DD [FTP Session 9 xx.xx.xx.xx] ~securer(1) ENTERING state = 1
2024-04-03T20:36:18.220Z DD [FTP Session 9 xx.xx.xx.xx] calling tls_layer_->set_alpn()
2024-04-03T20:36:18.220Z DV [FTP Session 9 xx.xx.xx.xx] tls_layer_impl::server_handshake()
2024-04-03T20:36:18.220Z DV [FTP Session 9 xx.xx.xx.xx] tls_layer_impl::continue_handshake()
2024-04-03T20:36:18.220Z DD [FTP Session 9 xx.xx.xx.xx] ~securer(1) EXITING state = 2
2024-04-03T20:36:18.220Z DD [FTP Session 9 xx.xx.xx.xx] tls_layer_impl::on_send()
2024-04-03T20:36:18.220Z DV [FTP Session 9 xx.xx.xx.xx] tls_layer_impl::continue_handshake()
2024-04-03T20:36:18.281Z DD [FTP Session 9 xx.xx.xx.xx] tls_layer_impl::on_read()
2024-04-03T20:36:18.281Z DV [FTP Session 9 xx.xx.xx.xx] tls_layer_impl::continue_handshake()
2024-04-03T20:36:18.281Z DD [FTP Session 9 xx.xx.xx.xx] TLS handshakep: Received CLIENT HELLO
2024-04-03T20:36:18.281Z DD [FTP Session 9 xx.xx.xx.xx] tls_layer_impl::failure(-8)
2024-04-03T20:36:18.281Z !! [FTP Session 9 xx.xx.xx.xx] GnuTLS error -8: A packet with illegal or unsupported version was received.
2024-04-03T20:36:18.281Z !! [FTP Session 9 xx.xx.xx.xx] Control channel closed with error from source 0. Reason: ECONNABORTED - Connection aborted.
2024-04-03T20:36:18.282Z DI [FTP Session 9 xx.xx.xx.xx] Session 0x218cf2e21c0 with ID 9 destroyed.

[botg]

They are using secureblackbox

Based on the error message, that client is not secure at all, it is critically outdated and tries to use some antique version of TLS. They need to update their client, of if that is not possible, switch to a better client which is always possible.

[drawntogether]

Thanks