COMMAND
SmartFTP-D
SYSTEMS AFFECTED
SmartFTP-D Server
PROBLEM
Moritz Jodeit found a bug in the SmartFTP-D Server which will give
an attacker full access to the server, if he has the right to
write files on the server. For every user, the program is
checking if a special Userfile exists (sample: Username=hacker &
Userfile=hacker.FTP_User). If it exists, the configuration, like
password, rights, etc. will be read out of this file.
The program doesn't check for bad characters, so by using "..\"
you can switch to other directorys. If an attacker has an account
on the machine, where he can write files, he can use this to get
full access to the whole machine! Let's take this example: Upload
directory is D:\Upload and SmartFTP-D is installed in
D:\Program Files\SmartFTP Daemon. An attacker would upload a
file called exploit.FTP_User, which includes his own password and
the rigths, he wishes to have. If he now uses the Username
"..\..\..\..\..\Upload\exploit", his uploaded Userfile will be
used and he can login.
SOLUTION
Mindstorm networks has been informed about this bug and a fix
should be available soon.