Technical information

Network Security White Paper ver. G.1.2
Page 12 of 72
1-3 FTP
1-3-1 Function Overview
The FTP (File Transfer Protocol) service is compliant with RFC 959. TCP port 20 is used for the
FTP-data service and TCP port 21 is used for the FTP-control service. In order to work with the products,
FTP clients must be compliant with RFC 959.
The following functions are provided by the FTP service.
• Submitting a print job
• Downloading the files listed in the table below
• Remote Firmware Updates
File name Description Attribute
Syslog System log Read-only
Stat Printer Status
Read-only
Prnlog Print log Read-only
Info Printer Information Read-only
Help Help Read-only
Fax application files:
These cannot be seen
by users.
rwx - - - - - -
Fax job log
Fax counter
Fax address book
SmartDeviceMonitor for
Admin/Client is required
to read these files.
RFU requires machine administrator privileges. When Web Smart Device Monitor is used for RFU, TCP
port 10020/10021 is used to send firmware files via the FTP protocol. However, port 21 is used to
negotiate the transfer. All 3 ports must be open. RFU is a proprietary process defined by Ricoh and is
extremely difficult to emulate. However if a strict security policy is to be maintained, that port can be
closed via TELNET.
1-3-2 Potential Threats:
Destruction, Corruption and Modification of the File System
Although the FTP service permits write-access, any files that are received by the printer are considered
to be a print job or firmware.
When the embedded FTP server receives an executable file, the product prints a binary representation
(garbage characters) of the data contained in the executable. As for firmware, a dedicated account and