Fax/Network Data Security and Lexmark Multifunction Products

Version 3.3

October 2010

Contents

Overview....3 Applicable Products....3 The Proposed Concern.... 4 The Practical Considerations...5 No Control of the Device via Phone Line... 5 Modem and INA are Separate by Design....6 Modem is Configured for Fax Only....6 No Support for the PS Fax mechanism...7 Phone Line Does Not Provide Means to Update Firmware..7

Summary.....8

Overview
Lexmark offers a variety of multifunction products that provide both network capability and fax modem capability. In environments where network security is critical, the combination of these two features on a single device has caused some concern. The purpose of this document is to address those concerns by exploring the conceivable ways that security could be breached by this device, and to describe the reasons why the design and implementation of Lexmark MFPs make this sort of abuse impractical.

Applicable Products

This document applies to the following MFPs: Lexmark X463 Lexmark X464 Lexmark X466 Lexmark X651 Lexmark X652 Lexmark X654 Lexmark X656 Lexmark X658 Lexmark X734 Lexmark X736 Lexmark X738 Lexmark X772 Lexmark X782 Lexmark X792 Lexmark X850 Lexmark X850 (4) Lexmark X852 Lexmark X854 Lexmark X860 (4) Lexmark X862 (4) Lexmark X864 (4) Lexmark X925 Lexmark X940 Lexmark X945

The Proposed Concern

The issue that raises concern is the presence of a fax modem on a device that also includes a network adapter. The fax modem, by nature, is: 1. Inherently bidirectional; it is capable of sending information to and from the MFP. 2. Inherently connected to the outside world; assuming the modem is connected to a phone line, the device is theoretically open to being accessed from anywhere. Based on these two attributes, it has been proposed that a security exposure may be present. Couldnt someone connect to the MFP via the modem and then somehow get information off of the network, thus exposing the customers network to inappropriate access?
Phone Line: - inherently open access - inherently not secure - inherently bidirectional
Internal Network: - secure - restricted access
Figure 1.0 The Proposed Exposure
The Practical Considerations
There is a long list of reasons why the presence of a fax modem on a device that also includes a network adapter is not a security exposure. This document explores each of these points in more detail: There is no support for controlling the device via the phone connectionone cannot dial into the device and interact with it via FTP, Telnet, or any similar mechanism. The modem and network adapter hardware are on separate cards and cannot communicate directly with one another. This prohibits data from crossing over between the two channels. The modem is configured to send and receive fax only, not data. The modems configuration is limited and controlled by the MFPs firmware. The MFP firmware does not allow arbitrary data to be exchanged over the fax modem, only facsimile data representing page images can be exchanged. The avenues by which the MFPs firmware can be updated are secured, and unauthorized firmware and software cannot be placed onto the MFP. All these factors prevent the interaction of the fax modem and network adapter hardware from providing a security exposure.
No Control of the Device via Phone Line Many devices that support an analog phone modem do so to allow the device to be controlled remotely, via the phone line. On such devices, one can call the device and interact with it: turn it on or off, change its settings, and so on. Typically, this would occur over some sort of management session, such as Telnet. However, the presence of an analog phone modem does not automatically involve any such mechanism. In order for the device to allow such interaction, the support needs to be built in and intentionally provided. Lexmarks products do not include or allow for this sort of control. No Lexmark MFPs allow for any sort of configuration via the phone line. There are no diagnostic modes by which any external mechanism can control or reconfigure the behavior of the modem. The only function that the analog phone modem is capable of exchanging is fax information. It does not allow for configuration or any sort of remote control of the device, and it does not allow any avenue to access the network to which the device is connected.

Modem and INA are Separate by Design Lexmark MFPs use a third-party fax chip to handle analog-to-digital processing, while the rest of the fax modem process is handled directly by Lexmark firmware. The internal network adapter function is implemented separately from the modem capabilities, and the two functions are implemented on separate circuit cards; the fax card is connected via a cable to a daughter card, while the network connection is on the MFPs motherboard. The fax processes are handled directly by the Lexmark firmware, as is the network adapter interaction, and the Lexmark firmware is designed to prohibit direct interaction between the fax and network components.
Daughter Card Network Connection
MFP Motherboard Phone Connection Fax Card Figure 2.1 Separation of Modem and Network Function on Lexmark MFPs
Modem is Configured for Fax Only Control of the fax functionality is incorporated directly into the Lexmark firmware. The fax chip that sends and receives data over the phone line is directly controlled by the Lexmark firmware. The modem chip is in a mode that is even more restrictive than Class 1 mode, and it relies on the Lexmark firmware for composition and transmission of fax data. The firmware explicitly disallows the transmission of frames in data mode and only allows for the sending and receiving of facsimile jobs.
No Support for the PS Fax Mechanism Some fax devices employ a mechanism known as PS Fax, or PostScript File Transfer. When two fax devices support PS Fax and connect via an analog phone session, PS Fax allows a print job to be transmitted in its original PostScript format. This is faster and produces higher-quality output than converting the job to a bitmap at the sending end and transmitting the bitmap. However, the ability of the receiving device to accept non-image data creates a security exposure. The PostScript job itself could potentially include malicious function(s), and the support for opening the connection for non-image data could leave the device vulnerable to other sorts of transmissions. For these reasons, the PS Fax capability is not supported on Lexmark MFPs.
Phone Line Does Not Provide Means to Update Firmware Because the only way to change the behavior of the modem would be with modified firmware, the question of how that might be accomplished can be reasonably posed. Because the network connection is secure, the avenue of concern is the phone line as it is inherently connected to the outside world.
The nature of the Lexmark firmware and the modems fax operation, however, is to accept only fax framesthese are frames that contain image data. When these frames are combined, they are assembled and wrapped in PostScript commands and submitted to the MFPs interpreter as image data. There is no other data path available, and no way for data that comes in via the fax to be treated as anything but a fax image. If the data that is received does not represent an image, the data is purged as an invalid PostScript job. There is no avenue by which modified firmware (or any sort of executable code) could be packaged as a fax job and become operable within the printer or MFP.

When accessing the MFP via the internal network, there are significant safeguards in place to disallow the modification of the MFPs firmware. One example is the requirement that any firmware upgrade is digitally signed by Lexmark, using Lexmarks private encryption key. This disallows any firmware, except that which is produced and approved by Lexmark, from being placed onto the MFP device.

Summary

While the initial reaction to an MFP device that contains a modem and a network adapter in close proximity might raise a concern that a potential security exposure exists, such a concern is not warranted. The Lexmark MFP implements the fax and network features in such a way that the hardware and firmware are both designed to keep the fax and network mechanisms separate, and the nature of the MFP restricts the addition or replacement of the Lexmark firmware.
Copyright 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Lexmark International, Inc. All rights reserved.
PostScript is a registered trademark of Adobe Systems Incorporated in the United States and other countries. This white paper does not constitute a specification or warranty. All rights and remedies concerning products are set forth in each products Statement of Limited Warranty.

Printer, MFP, Option, and Stand Compatibility
[Click the configuration of your choice to see the details.]
How to read this document...... 2 Supported maximum configurations for Lexmark X658e MFP.... 3 Supported maximum MFP configurations for base 16M1216.... 4 Supported maximum Lexmark X651, X652, X654, X656 MFPs configurations for desktop use and use with the swivel cabinet. 5 Supported maximum configurations Lexmark X73x MFPs with base 16M1210... 6 Supported maximum configurations for Lexmark X73x MFPsfor desktop and use with swivel cabinet... 7 Supported maximum configurations for Lexmark T65X.... 8 Supported maximum configurations for Lexmark C73x.... 11 Supported maximum configurations for printer stand 16N1708 with or without scanner shelf 21J0055.. 12 Supported desktop/swivel cabinet maximum configurations for Lexmark C546dtn and X546dtn.. 13 Legacy information...... 14
Scanner shelf information...... 14
Supported maximum configurations for desktop use.... 15 Supported maximum configurations for swivel cabinet 3052765.... 16 Supported maximum configurations for furniture stand 16C0369 and 16C0379... 17 Supported maximum configurations for furniture stand 16C0389.... 18 Supported maximum printer configurations for base 22G0544.... 19 Supported maximum configurations for base 22G0544with scanner plus shelf 21J0050... 20 Supported maximum MFP configurations for base 22G0544.... 21 Supported maximum configurations for base 22G0544 with scanner.... 22 Supported maximum configurations for base 10G0080..... 23 Supported maximum configurations for base 10G0080 with scanner.... 24 Supported maximum configurations for printer stand 16N1708 with or without scanner shelf 10B1755.. 25
2009 Lexmark International, Inc. All rights reserved. January 2010
How to read this document
The following tables show the maximum possible configurations for each printer or multifunction printer (MFP), MFP option, and furniture stand. See the following illustration on how to read the table.
This furniture stand supports these printers or MFPs.
These optional scanners are supported.
Printers or MFPs supported: T630, T630n, T632, T632n, T634, T634n Scanners supported: 3100, 3200, X4500

Printer with: MFP Option

Duplex

250-sheet drawers 1 2

Optional 500-sheet drawers 1
Optional 2000-sheet drawers 4 1
YES YES YES YES YES YES YES
YES YES YES YES NO NO YES
Each row represents a supported maximum configuration. If an option is removed from a particular row, then the information would still indicate an acceptable configuration. For example, in the highlighted row, the supported configuration shows that: An MFP (scanner on top of a printer) with a duplex unit, three 250-sheet drawers, and one 500-sheet drawer is one of the maximum configurations possible on this particular furniture. The configuration above is still acceptable with the removal of one or more of the options (scanner, duplex unit, 250-sheet drawer, or 500-sheet drawer). The configuration is not acceptable with any additional options listed in the chart.
Supported maximum configurations for Lexmark X658e MFP

Caster base

MFPs supported: X658e A maximum of four 550-sheet drawers (standard or optional) are supported. One 550-sheet drawer is part of the base unit, so up to three additional optional drawers are allowed when configuring your printer.
Note: Caster base is standard.
Supported maximum MFP configurations for base 16M1216
MFPs supported: X651e, X652e, X654e, X656e

MFP with:

Optional 250-sheet drawers 1
Optional 550-sheet drawers or 5.1-inch spacers 1
Optional 2000-sheet drawer 4 1

Notes:

The spacer(s) must be below all drawers, but they cannot be used with the 2000-sheet drawer. The optional 2000-sheet drawer must be below any other drawers. At least one input drawer or spacer is required with this base.
Supported maximum Lexmark X651, X652, X654, X656 MFPs configurations for desktop use and use with the swivel cabinet

Swivel cabinet

Part Number 3052765

MFP configured with: 1

Optional 250-sheet drawers
Optional 550-sheet drawers or 5.1-inch spacers
Note: Be sure the total height of the selected configuration is appropriate for your office environment.
Supported maximum configurations Lexmark X73x MFPs with base 16M1210
MFPs supported: X734de, X736de, X738de
Optional 550-sheet drawers or 4.8-inch spacers 1
Supported maximum configurations for Lexmark X73x MFPsfor desktop and use with swivel cabinet

Placement 1

Desktop/swivel cabinet Desktop/swivel cabinet Floor
Optional 550-sheet drawers or 4.8-inch spacers 2
Optional 2000 sheet drawer 1
Supported maximum configurations for Lexmark T65X
An internal duplex unit is a standard feature on the.

Printers supported: T65X

Printer Placed on models the floor or on a desktop
T650, T652, T654 T656 Desktop/swivel cabinet
Optional 2000sheet drawer

Duplex Unit*

Optional 250-sheet drawers 1 2
Optional 550-sheet drawers or 5.1inch spacers 3 4

Optional caster base

PN 39V3588

Not needed

Inapplicable

Yes or No

* The optional duplex unit is available only on the Lexmark T650n. An internal duplex unit is a standard feature on the Lexmark T652dn,T654dn, and T656.

T650 Floor

May be used, but not required for safe operation
May be used, but not required for safe operation

T652, T654 T656

Included
T650, T652, T654 T656 Floor

Required

Supported maximum configurations for Lexmark C73x
Printers supported: C734, C736
Placed on the floor or a desktop

PN 39V3425

Optional 550-sheet drawers or 4.8inch spacers 1 2
Optional 2000-sheet drawer 1
May be used, but not required for safe operation

Desktop/swivel cabinet

Not applicable
Supported maximum configurations for printer stand 16N1708 with or without scanner shelf 21J0055
Printers supported: C772, C782 Scanners supported: 4600 MFPs supported: X772e, X782e

Printer with:

MFP Option
Optional 500-sheet drawers 1 2

YES YES NO

YES NO YES
If an optional duplex unit is installed:
The duplex unit must be directly under the printer for any of the listed configurations. All paper-handling options must be installed below the duplex unit.
Printer (without MFP option) can also support a maximum combination of one optional 2000-sheet drawer plus one optional 500-sheet drawer (with or without duplex). The printer stand 16N1708 is not used with the 2000-sheet drawer. An optional 500-sheet drawer is required when utilizing a 2000-sheet drawer and duplex unit. (The first option under a duplex unit must be a 500-sheet drawer.)

Supported desktop/swivel cabinet maximum configurations for Lexmark C546dtn and X546dtn
Printers supported: C546 MFPs supported: X546dtn
Printer or MFP configured with:

Optional Tray

PN 3051710
Legacy information Scanner shelf information
In order to place an MFP option on top of a supported monochrome printer, you must use one of the following shelves:
Part number 16A0503, which supports the following configurations:
MFP option X242 and X443 for T5XX, T61X, T62X printers MFP option 3100 and 3200 for T63X printers MFP X630, X632, X632s MFP option X4500 for T632 and T634 printers MFP X632e, X634e (shelf included) MFP option 4600 for T642(n) and T644(n) printers
Part number 10G1000, which supports the following configurations:
Part number 21J0050, which supports the following configurations:
If an MFP option and scanner shelf are installed, then no output options are allowed in the configuration. If an MFP option and scanner shelf are not installed, then all output options are supported. Scanner shelves must be attached directly to the printer.
Supported maximum configurations for desktop use
Printers supported:T630, T630n, T632, T632n, T634, T634n, T640, T640n, T642, T642n, T644, T644n Scanners supported: 3100, 3200, X4500 MFPs supported: X630, X632, X632e, X632s, X634e, X644e, X646e, X642e
MFP or MFP Option configured with:

Optional 500-sheet drawers 3 4
YES YES YES YES NO NO NO NO NO NO NO NO
YES NO YES NO YES NO YES NO YES NO NO YES
Be sure the total height of the selected configuration is appropriate for your office environment. If an optional duplex unit is installed:
Supported maximum configurations for swivel cabinet 3052765
Click a link as follows to see the supported configurations for the product:
T65x Desktop Configurations X65x Desktop Configurations C73x Desktop Configurations X73x Desktop Configurations C546 Desktop Configurations X546 Desktop Configurations
Supported maximum configurations for furniture stand 16C0369 and 16C0379

16C0369

16C0379
Printers supported: T630, T630n, T632, T632n, T634, T634n, T640, T640n, T642, T642n, T644, T644n Scanners supported: 3100, 3200, X4500, 4600 MFPs supported: X630, X632, X632e, X632s, X634e, X646e, X644e, X642e

The bottom of the printer should not reside more than 1.5 inches above the top surface of the printer furniture side shelves after installation. If an optional duplex unit is installed:
The bottom of the optional duplex unit should not reside more than 1.5 inches above the top surface of the printer furnitures side shelves after installation. The duplex unit must be directly under the printer for any of the listed configurations. All paper-handling options must be installed below the duplex unit.
The optional 2000-sheet drawer must be at the bottom of the stack of drawers.
Supported maximum configurations for furniture stand 16C0389
Printers supported: T630, T630n, T632, T632n, T634, T634n, T640, T640n, T642, T642n, T644, T644n Scanners supported: 3100, 3200, X4500, 4600 MFPs supported: X630, X632, X632e, X632s, X634e, X644e, X646e, X642e
YES YES YES YES YES YES YES YES YES
The optional 2000-sheet drawer must be at the bottom of the stack of drawers. Stability requirementStability tabs included with the furniture must be installed to meet safety requirements.
Supported maximum printer configurations for base 22G0544
Printers supported: T630, T630n, T632, T632n, T634, T634n, T640, T640n, T642, T642n, T644, T644n Scanners supported: See the following page

NO NO NO NO NO NO NO NO

YES YES YES YES YES YES YES YES
The optional 2000-sheet drawer unit must be at the bottom of the stack of drawers. At least one optional input drawer is required with this base.
Supported maximum configurations for base 22G0544with scanner plus shelf 21J0050
Printers supported:T642, T642n, T644, T644n Scanners supported: 4600 MFPs supported: See the following page
Optional 10-inch cabinet 4
The optional 2000-sheet drawer must be at the bottom of the stack of drawers. The optional 10-inch cabinet must be at the bottom of the stack of drawers. At least one input drawer or optional 10-inch cabinet is required with this base.
Supported maximum MFP configurations for base 22G0544
MFPs supported: X646e, X644e, X642e
Optional 10inch cabinet 4 1
YES YES YES YES YES YES YES YES YES YES
Supported maximum configurations for base 22G0544 with scanner
Printers supported:T630, T630n, T632, T632n, T634, T634n Scanners supported: 3100, 3200, X4500 MFPs supported: X630, X632, X632e, X632s, X634e

YES YES YES YES YES YES

YES YES YES NO YES YES
The optional 2000-sheet drawer must be at the bottom of the stack of drawers. At least one optional input drawer is required with this base.
Supported maximum configurations for base 10G0080
Printers supported: T630, T630n, T632, T632n, T634, T634n, T640, T640n, T642, T642n, T644, T644n MFPs supported: See the following page
Supported maximum configurations for base 10G0080 with scanner
Printers supported: T630, T630n, T632, T632n, T634, T634n Scanners supported: 3100, 3200, X4500 MFPs supported: X630, X632, X632e, X632s, X634e
Supported maximum configurations for printer stand 16N1708 with or without scanner shelf 10B1755
Printers supported: C760, C762 Scanners supported: X4500 MFPs supported: X762e
The duplex unit must be directly under the printer for any of the listed configurations. All paper-handling options must be installed below the duplex unit. Printer (without MFP option) can also support a maximum combination of one optional 2000-sheet drawer plus one optional 500-sheet drawer (with or without duplex). The printer stand 16N1708 is not used with the 2000-sheet drawer. An optional 500-sheet drawer is required when utilizing a 2000-sheet drawer and duplex unit. (The first option under a duplex unit must be a 500-sheet drawer.)