Rule:  

--
Sid:
360

--
Summary:
This event is generated when an attempt is made to exploit a known vulnerability in Serv-U FTP from Rhino Software Inc..

--
Impact:
Possible theft of data and control of the targeted machine leading to a compromise of all resources the machine is connected to.

--
Detailed Information:
Serv-U FTP from Rhino Software Inc. is an FTP server for Windows 2000, NT and 9x systems.

An attacker can download and upload files on the same partition as the ftp root. The attacker can use a standard user account with write and read access to a home folder.

The vulnerability appears in Rhino Software Inc. Serv-U FTP Server version 2.5a-h. A Unicode support implementation error was made, which allows an attacker to submit %20..%20.. to receive a "..", which allows an attacker to traverse the directory structure of the server. 

--
Affected Systems:
Rhino Software Inc. Serv-U 2.4
Rhino Software Inc. Serv-U 2.5
Note: Rhino Software Inc. Serv-U 2.5i is not affected.
Rhino Software Inc. Serv-U 3.0 beta

--
Attack Scenarios:
Any standard user can break into the system root and access any file. An attacker could also guess a login and weak password, login and use the directory traversal to gain the Serv-U FTP Server's configuration file. The configuration file can be modified to give "execute" rights, uploaded using %20. directory traversal and trojans can be installed.

--
Ease of Attack:
Simple. No exploit code is required.

--
False Positives:
None Known.

--
False Negatives:
None Known

--
Corrective Action:
Upgrade to the latest non-affected version of the software.

Check FTP log files for signs of compromise.

--
Contributors:
Original Rule Writer Unknown
Snort documentation contributed by Ueli Kistler, <u.kistler@engagesecurity.com>
Sourcefire Vulnerability Research Team
Nigel Houghton <nigel.houghton@sourcefire.com>

-- 
Additional References:

OSVDB:
http://www.osvdb.org/464

--
