Original Advisory: Tuesday, March 25, 2003

Severity: Medium - High

Description: Unencrypted tax-return information saved in C:\My Documents

by default can pose security risks, and may disclose financial/personal

information to the Internet via peer-to-peer (P2P) networks.

Version: Tested on the version released March 20, 2003

Authors: David Coomber and Nathan Wosnack were involved in the research

and development.

Tax Software Background:

MyTaxexpress 2003 is a CCRA (Canada Customs and Revenue Agency) certified

GUI application developed by ExpressInfo Software that allows Canadian tax

payers located in Alberta, British Columbia, and Ontario to work through

their tax returns and file them electronically using a tax filing system

known as NETFILE.

Description of the problem:

If you decide to save your return, your personal information is saved to

your computer unencrypted in the directory C:\My Documents by default with

a *.ret extension. The problem with this is two-fold; if someone is able

to access this file, then all they would need to do is open it with a text

editor such as Notepad to reveal personal information. The personal

information disclosed includes your full name, your address, your social

insurance number, your earnings, spending claims, where you work, etc.

Saving your tax files in C:\My Documents makes it easier to get a hold of

since many Microsoft Windows users share C:\My Documents when using P2P

programs without understanding the consequences. Also, Many P2P file-

sharing networks have been known to share the C:\My Documents folder. One

such example of a file sharing program that does this is a program

called 'Kazaa' (with K++ extensions). With a simple query on Kazaa,

looking up file names such as 'taxes 2003.ret', 'taxes.ret', one could

gather large amounts of data on unsuspecting users that have C:\My

Documents shared.

Recommendations:

Due to the fact that MyTaxexpress does not encrypt your tax return when

saved to disk, and stores it in C:\My Documents by default, the risk of

having personal financial information stolen and used for illegal purposes

is high. In order to protect this financial information from disclosure

and misuse, we recommend saving your returns in a different directory and

encrypting your returns (and all other personal information) with a strong

encryption program such as Blowfish for Windows(1) or similar.

Related Links:

http://www.pivx.com/ - Related advisories focusing on United States tax

software.

http://www.hypervivid.com/ - Information, Telecom and Wireless Security

Consulting Firm.

Vendor Contact:

http://www.mytaxexpress.com/ - ExpressInfo software.

Have any questions or comments?

e-mail: advisories (at) hypervivid (dot) com [email concealed]

Copyright © 2003, Hypervivid Solutions Incorporated. All Rights Reserved.

(1) Note: We are not affiliated with any products or services mentioned on

this page, we provide the links solely as a convenience to the reader.

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