Incorrect filename parsing - FTP Client

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ninix
Guest

Incorrect filename parsing - FTP Client

There seems to be a issue if a filename starts with a space character (or multiple spaces).
The FTP client will trim out all spaces from a filename and display the rest of its string (this can also be a issue with a space as the last character)

I've discovered this after some users reported that they can't delete there own files (They have full read/write access) and the message was that "550 The system cannot find the file specified.".

So I've start investigating the issue and with multiple FTP clients: WinSCP, FileZilla, Total Commander, etc... All with the exact problem. The file can't be renamed/deleted/open/etc.
The server is a "Microsoft FTP Service - Windows 2008 R2" which seems to accept filenames starting with one or multiple space characters :(

Command:   DELE A D R E S A      Document1.doc
Response:   550 The system cannot find the file specified.

Command:   RNFR A D R E S A      Document1.doc
Response:   550 The system cannot find the file specified.

I know, is one of the weirdest names I've seen so far....

So, to solve this I've used old school FTP command line

ftp> o my.ftp.server
Connected to my.ftp.server.
220-Microsoft FTP Service
[...]
230 User logged in.

ftp> cd file/path
250 CWD command successful.

ftp> dir
200 PORT command successful.
125 Data connection already open; Transfer starting.
02-27-17  07:54AM               544768  A D R E S A     Document1.doc
02-27-17  08:45AM               753624  A D R E S A     Document2.doc
226 Transfer complete.
ftp: 119 bytes received in 0,00Seconds 59,50Kbytes/sec.

ftp> delete "A D R E S A     Document1.doc"
550 The system cannot find the file specified.

ftp> mdelete *
200 Type set to I.
mdelete  A D R E S A     Document1.doc? yes
250 DELE command successful.
mdelete  A D R E S A     Document2.doc? no

ftp> delete " A D R E S A     Document2.doc"
250 DELE command successful.

So, by using a buggy FTP server witch accepts unusual filenames (starting with space characters) combined with weird people writing those names the result is no more access to those files anymore.

Please redesign the filename parsing for "LIST" command, so it will accept those anomalies.

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martin
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martin avatar
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Re: Incorrect filename parsing - FTP Client

Thanks for your suggestion.
Will see if more people ask for this.

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