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Re: DoS on ftp port

  • From: Anthony D Cennami
  • Date: Tue May 21 13:04:47 2002


In addition to David's suggestion, you would also want to ensure that newly create files are umasked unreadable as well. Should the directory be masked unreadable but still executable (which it must be to actually enter it) users could still externally link to the files, even though one could not view them in a directory listing.



[email protected] wrote:

Rob Thomas wrote:

There is a huge increase in FTP scanning as well as the building of
warez botnets.  The warez scanning is generally for anonymous FTP
servers with plentiful bandwidth, copious disk space, and generous
write permissions.  ...

One things I know of that helps here is to make sure you never have a
single directory that is both readable and writeable to an anonymous
user.

In general, restrict writing to users with logins and passwords.  If you
must have an anonymous-write directory (like an incoming folder), make
sure that that directory is not also readable by anonymous users.

This probably won't eliminate all the abuse, but it should make it
impractical enough that the warez servers will probably start looking
elsewhere.

-- David