I have an old site that is in danger of being compromised as many of the directories and files have permissions set to 777. However, when I try to change them to 555 via FileZilla I get the error

500 'SITE CHMOD 555 filename': command not understood

Googling it only reveals issues relevant to connecting to the server, but I can do that, as well as up and downloading files. I'm not sure what this means exactly. Is it that my account doesn't have sufficient permissions to make these changes?

  • Do you have SSH access? Commented Feb 20, 2013 at 1:09
  • @Riboflavin no, just FTP
    – MeltingDog
    Commented Feb 20, 2013 at 1:13
  • 2
    Are you on a Windows server? chmod is a unix command.
    – MrWhite
    Commented Feb 20, 2013 at 10:10

2 Answers 2


Better change the permissions either via your File manager( which should be available in your control panel) or directly via SSH access by using the chmod command.

  • As w3d pointed out in his comment, chmod, a UNIX/LINUX command is not available on a Windows Host. FileZilla uses the chmod command, and AFAIK, there is no equivalent in Windows. The control Panel in Plesk I assume is akin to the Security Tab of the Properties Window in Windows, which is why you are able to "via the control panel"
    – eyoung100
    Commented Sep 17, 2014 at 21:22

It is likely caused by your web host disallowing the chmod command over FTP. If you have a control panel available through your host I would use that to try to change the folder permissions and see if it works that way.

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