security flaw - has this been seen before - Execl import

[fauxn]

Hi all,

This is potentially a major problem. In Excel it's possible to protect a workbook preventing anyone from modifying data validation. However, upon importing the Excel file into OOc the protection is able to be turned off without the use of the password set in Excel effectively bypassing the workbook protection. This also occurs visa versa!

Has this been noticed before (if not I'll add this to the bug list)?

Cheers
Noel

[noranthon]

Comments have been made about the former and I gained the impression that that was regarded as a security flaw in excel. If it happens vice versa, I believe it would be in OOo's interest to file an issue.

[fauxn]

The latter was the case on a Mac, I'll test it on a windows machine, either way I'll post a bug on the OO site.

Cheers
Noel

[Villeroy]

There is no password-protection in Excel. You can read the entire file, when you know about the file format. There is just a block of bytes, indicating that the app should ask for a password if the block has other bytes than [...]. When using a password with a Calc-document the file gets encrypted. Same with those VBA-passwords. If you are curious about a VBA-macro in a document, just open in OOo.

[9point9]

[noranthon]

The flaw is that it apparently works the other way around. He was able to bypass protection on an OOo document opened in the other programme.

[Villeroy]

Sorry for getting this wrong. You have an issue with the protection data-validation rather than file-protection. Calc treats this feature as an advanced edit help, preventing typos and misleading entries. It's not a security-feature, able to keep integrity of your data. This can be done more easily and reliable with a *simple* database. A spreadsheet is designed to keep any kind of data in any row or column.

[9point9]

[noranthon]

Which exposes a weakness in this whole strategy of MS-compatibility. Ho-hum.

[David]

Add it to Excel's bug list. A long time ago now I noticed that a "protected" Excel file could have the protection bypassed by simply opening it in Quattro Pro. That may not always work, but certainly did at that level.

I have not had the opportunity, or urge to test Quattro Pro's protection capability in the same way. Perhaps someone else, or yourself, might have the time to do this?

David.

[fauxn]

Hi all,

I tested the reverse on a Window$ box, as expected, the same result.

Given this problem, there should be a warning that the protection will be void if saved in another format such as Excel, untill M$ open up Excel sometime in the next 1K years. Not just the standard warning that some features maybe lost.

Is this protection void if saved in an other formats such as the open document format?

Ok, I accept that it's not a bug in OO, but the above comment should be come a feature request. This issue may encourage M$ to either open the Excel format a little more or adopt the open document format.

Cheers
Noel

[Villeroy]

*Their* future is DRM (newspkeak: "trusted computing").
http://en.wikipedia.org/wiki/Digital_Rights_Management

[9point9]

[sonrock3]

Ditto!
As a new OOo user I was surprised and shocked to discover this security flaw. But it's useful to know (from one post here) that I cannot rely on file passwording to protect my spreadsheets from users being able to modify them (e.g. to remove my name + copyright statements so that they can re-present them as there own!)

Or put it another way, can anyone suggest how to make my files properly secure (from users modifying them an dpreferably even to stop users saving them)?
_________________
Stephen on rock 3

[9point9]

If you're talking about Excel files, there is no way. If you just have a table of numbers that you want to present then do it as a PDF.
_________________
Arch Linux
OOo 3.2.0

OOoSVN, change control for OOo documents:
http://sourceforge.net/projects/ooosvn/