Donato Ferrante

Application: Fastream NETFile FTP/Web Server
http://www.fastream.com/

Version: 6.5.1.980

Bug: Denial Of Service

Date: 19-Apr-2004

Author: Donato Ferrante
e-mail: fdonato (at) autistici (dot) org [email concealed]
web: www.autistici.org/fdonato

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

1. Description
2. The bug
3. The code
4. The fix

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

----------------
1. Description:
----------------

Vendor's description:

"Secure, multi-threaded FTP/HTTP server combined, featuring automatic
virtual links, U/D ratios, quotas, authentication and extremely fast
directory and file caches. Other features include: User and group
permissions with permissions for all standard FTP and HTTP commands.
Serving from behind NAT/PAT. HTTP file uploading and management.
Free for personal use; professional license is required for commercial
usage."

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

------------
2. The bug:
------------

The program is unable to manage nonexistent usernames in the login
procedure. So attacker can deny the ftp service by sending crafted
USER and PASS strings.

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

-------------
3. The code:
-------------

To test the vulnerability:

1-a. connect to the ftp server and when it asks
for the USER, type: anUsername
for the PASS, type: aPassword

1-b. send to the ftp server something like:
USER anUsername
PASS aPassword

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

------------
4. The fix:
------------

Bug fixed in the version 6.5.1.981.

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

[ reply ]