BugTraq
PivX Advisory MK002A Intuit TurboTax Information Disclosure Vulnerability Mar 13 2003 07:25AM
Mike Kristovich (mkristovich pivx com)


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Mike Kristovich, PivX Security Advisory MK#002A

Date: January 10, 2003

Application: Intuit TurboTax

Version: All versions up to current.

Bug: Information in saved Tax Returns discloses Social Security

Number, Full Information, and more..

Risk: Can allow for identity theft, information disclosure

Author: Mike Kristovich, Security Researcher, PivX Solutions, LLC

e-mail: mkristovich (at) pivx (dot) com [email concealed]

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Sections:

1) Introduction

2) Bug

3) Proof of concept code.

4) Fix

5) Philosophy

6) Closing comments..

7) Contact

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1) Introduction

According to the Jupiter report, 31 percent of online

households intend to file their taxes over the Web this

year, up from the 30 percent reported by the Internal

Revenue Service (IRS) last year. The IRS plans to receive

80 percent of all returns electronically by 2007.

Complaints about identity theft have risen 73 percent from

a year ago, according to a new report from the Federal Trade

Commission.

With the influx of e-tax filers and the rise in identity

theft PivX believes this vulnerability should be taken

quite seriously. Someone with a minimal set of computer skills

could locally or remotely obtain confidential information

on multitude of users.

TurboTax (Advisory #MK002A) and TaxCut (#MK002B) both

save their contents to the hard drive. These files are

unencrypted, and even with a simple text editor, you can

see all the information you would in the tax return.

These files can be accessed in any number of ways, but the

most likely way would be through unprotected windows shares.

Many ISPs have blocked port 139 among others, but in newer

versions of Windows, you may also be sharing on port 445.

Port 445 is Microsoft Directory Service. A large number

of tax files and the identities within can be harvested

in a matter of minutes to hours.

Another key method to extract these files by means of a P2P

file sharing application such as Limewire, KaZaa, Morpheus,

etc etc. Many users have their P2P applications misconfigured

and this is supported by doing a quick search on the tax file

extension listed below. See the below KaZaa screenshot of a

local-range search for tax files. A full network search could

yeild thousands upon thousands of results.:

http://www.pivx.com/kristovich/images/kazaatax.jpg

The bottom line is:

- Be aware of what you are sharing to the public -

There are other ways files could be collected, such as

through a worm, an exploit, or a trojan horse.

Intuit TurboTax files (.tax) are usually named this way:

"YYYY <Last> <First_I.> Tax Return.tax"

and the files are usually located off the root of the drive,

in a directory such as "Tax02" "Tax01" "Tax99", etc.

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2) Bug

Just a small insecurity can lead to a lot of information.

For TurboTax, you can do a simple scan for the

last name of the person, and closely following it, you'll

see their social security number. Browse around that area

of the file and you'll see their street address and more.

If you use turbotax, load up one of your files in a binary

editor and check it out for yourself.

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3) Proof-of-concept code

No proof of concept needed, just use a hex editor or text

editor as files are associated:

(.tax) Hex Editor

View Example Screenshot:

http://www.pivx.com/kristovich/images/taxfile.jpg

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4) Fix

Intuit has been contacted and is currently working on a solution.

They have informed us that they will now be encrypting files starting

in the next version.

The best solution is to move saved tax files to a more private place,

such as a CD-R. Even if a drive is not shared to the public, you may

still be at risk through other exploits or trojan horses.

As mentioned by Becky Worley in a TechTV article tuesday,

[http://www.techtv.com/news/security/story/0,24195,3420432,00.html]

Easy Crypto Deluxe is recommended to password protect your

sensitive data. You can download it here:

http://www.handybits.com/easycrypto.htm

We thank Intuit for the extremely fast response on this one,

keep up the good work!

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5) Philosophy

Full disclosure can lead to a quick fix, and prevent a problem before

it gets into the wrong hands.

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6) Closing comments..

In the electronic world, consider nothing secure. You should never

store this type of information on a live computer. Be careful.

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7) Contact

Any questions, comments, complaints, technical questions:

Mike Kristovich, Researcher

PivX Solutions, LLC

mkristovich (at) pivx (dot) com [email concealed]

Other Inquiries:

Geoff Shively, CHO

PivX Solutions, LLC

gshively (at) pivx (dot) com [email concealed]

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