A Major design Bug in Camouflage 1.2.1 (latest)

2007-01-1100:00:00

vulners.com

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Direct Link: http://homepage.mac.com/adonismac/Advisory/steg/camouflage.html

Disclaimer

This material is presented for informational purposes ONLY. I do not condone or encourage vandalism or theft.

I do not accept any liability for anything anyone does with this information. So, don't shoot the messenger.
Remember: Use a computer in ways that ensure respect for your fellows.

Author

Adonis a.K.a. NtWaK0
Abed a.K.a. NoPh0BiA

Affected Product

Camouflage 1.2.1 (latest).
http://camouflage.unfiction.com/

Bug Type and Date

Type: Very Bad Design
Date: 01/07/2007

Bug Results

Cracking encrypted (Camouflage 1.2.1) files without any bruteforce.

WHY LOSING TIME ON MATH AND BRUTEFORCE WHEN YOU CAN PLAY WITH YOUR HEX EDITOR :-).

Bug Description

Firstly, computer forensic investigators can take advantage of this bug to access file protected with (Camouflage 1.2.1) without the knowledge of the original password. Now it is time to check your cold cases for steganography files.

You can crack (Camouflage 1.2.1) encrypted files very easy, in fact in less than two minute. The problem is similar to the bug I found in PGP last year.

(Camouflage 1.2.1) leave a footprint after you stag a file.
If you look at the end of your stagged file you will notice the following:
http://homepage.mac.com/adonismac/Advisory/steg/camouf3.jpg

So now we have identified the stagged file our next step is to access the HIDDEN messages or files without cracking the password, here is how.

Proof-of-Concept (THIS WILL WORK HIDDEN FILES)

For screen capture please check http://homepage.mac.com/adonismac/Advisory/steg/camouflage.html

Step 01

We use a file cover (carrier file) called "Adonis_Carrier_File1.jpg"
We will hide inside it a file called "Adonis_Hidden_File1.txt"
We will right click "Adonis_Hidden_File1.txt" and select camouflage
We will use a password "aaaa"
We generated the stagged file we will call it "Adonis_Camouflage_Stagged_File.jpg"

http://homepage.mac.com/adonismac/Advisory/steg/camouf1.jpg

Step02

NOTE: We will use different carrier and different input file to show you it will work even if you have different input and different carriers.

To access the hidden file WITHOUT the original password "aaaa" we will do the followings:

We use a file cover (carrier file) called "Adonis_Carrier_File2.jpg"
We will hide inside it a file called "Adonis_Hidden_File2.txt"
We will right click "Adonis_Hidden_File2.txt" and select camouflage
We will use a password "a"
We generated the stagged file we will call it "Adonis_break_camouflage.jpg"
We will open Both pictures in a hex editor
We will replace as indicated in the screen capture below "Adonis_Camouflage_Stagged_File.jpg" with the one from "Adonis_break_camouflage.jpg"
We will Save the file.
We will right click "Adonis_Camouflage_Stagged_File.jpg" and select camouflage and use "a" as password. YES we overwrite the password with something we know.

Simple hein !!!

Now time to break camouflage.

We will open "Adonis_Camouflage_Stagged_File.jpg" and "Adonis_break_camouflage.jpg" in hex edit. We will start from the END of the file and try to locate 00 02 63 (like 10 lines from the end of the file).

Once we have located the values we start REPLACING from LEFT to right starting after 00 20 63 (63 is the first letter of the password a) (Do not replace 63 it is your password = a).

In this example I will replace the password aaaa with a. So I will replace F4 1B 43 with 20 20 20.

http://homepage.mac.com/adonismac/Advisory/steg/camouf2.jpg

To resume the password is saved starting from 00 00 20 00 (ANYTHING AFTER THIS POINT IS THE PASSWORD AND THIS CAN BE OVERWRITTEN AS YOU SEE)