LIST works but LIST -a causes 550

[gowner]

Hi folks,
on my FileZilla Server, when I send a LIST command, everything works fine, I see all files. But when I send LIST -a, I get a 550 error. The server is running on the system account and that account has full control permissions on the local folder. The user I am using has full read, write permissions as well. Can anyone help with this? Log entries are below:

<Date/Time> Info [Type] Message
<12/15/2023 12:20:11 AM> FTP Session 13 192.168.178.24 gowner [Command] LIST -a
<12/15/2023 12:20:11 AM> FTP Session 13 192.168.178.24 gowner [Response] 550 Couldn't open the file or directory
<12/15/2023 12:21:50 AM> FTP Session 8 192.168.178.24 gowner [Command] LIST
<12/15/2023 12:21:50 AM> FTP Session 8 192.168.178.24 gowner [Response] 150 About to start data transfer.
<12/15/2023 12:21:50 AM> FTP Session 8 192.168.178.24 gowner [Response] 226 Operation successful

[boco]

LIST -a means "list a directory or file with the name -a". As there is no such item, the error message is displayed. Working as intended.

Parameters to LIST are not supported by FileZilla Server. They violate the FTP specs and should have never existed.

[TechyUser46]

Parameters to LIST are not supported by FileZilla Server. They violate the FTP specs ...

Just to clarify, the FTP spec (RFC 959) certainly allows parameters for the LIST and NLST commands ("pathname", specified "directory", specified "file", or "system-specific file group descriptor"). See https://www.rfc-editor.org/rfc/rfc959.html

Code: Select all

LIST (LIST)
This command causes a list to be sent from the server to the
passive DTP.  If the pathname specifies a directory or other
group of files, the server should transfer a list of files
in the specified directory.  If the pathname specifies a
file then the server should send current information on the
file. ...

NAME LIST (NLST)
This command causes a directory listing to be sent from
server to user site.  The pathname should specify a
directory or other system-specific file group descriptor; ...

[boco]

By "parameters", I referred to the illegal parameters, like -a. A pathname is of course allowed, as the only one.

[bobfitz]

Is there any kind of workaround for this? I have no control over the FTP client that is using the LIST -a command. I can't force it to drop the argument since the command is automated. Also, this was not a problem until I upgraded from FileZilla Server 0.96. Appreciate any help.

[botg]

There are numerous issues with LIST. MLSD has been introduced in March 2007 as a replacement to address these issues. Are you saying that the client in use hasn't been updated in almost 17 years? That doesn't seem wise from a security perspective.

[bobfitz]

Unfortunately, yes. The devices sending the LIST -a command are built into a system board using a custom designed FTP client. I am at the mercy of the developer to make changes. I've since had to revert to using the old version 0.96 FileZilla server. Without that I'm unable to see the files on the server. Do you happen to know why LIST -a works in the old version, but not the new one?

[botg]

It's one of my biggest regrets. I unfortunately didn't know better back in the days. If I could turn back time, I would make sure to never have implemented the old server that broken way.

[bobfitz]

Well, I still appreciate the fact that the old version still functions. Thanks for making it available.