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Microsoft Word Forms Passwords Hacked
An anonymous reader notes: "SecurityFocus has published a hack that can be used to unlock Microsoft Word documents that have been password protected. The 'secure' file can easily be edited and the original password re-inserted, removing any trace of the modification. A ZDNet UK article says Dell uses password protected Word files to send quotes, which could make for a messy legal battle." This feature, known as 'Password to Modify', is not the password protection on the document itself, just the protection that restricts unauthorized editing of the file. This hack allows someone to download such a file, edit it, and restore the password...effectively allowing changes to the file to go potentially unnoticed.
There have been utilities to obtain Word passwords for quite a while. I've tested mine on Office 2000 and XP protected documents and had great success.
What's odd: The password returned by my tool of choice is not the same as the one actually stored - but when I enter this new password OR the original password into Word, the document is successfully unprotected. Some sort of odd math that makes more than one password work?
Example - I protected both a Word 2000 and Word 2002 document with the password "test" then ran them through my cracker. The cracker returned the password "QFQDOBCTGLHGEE" virtually instantly for both documents. Oddly enough, this new unusual password successfully unlocked both Word documents using Tools > Unprotect Document. Subsequent testing reveals that the original password will also unprotect the document.
So, if such passwords can easily be bypassed anyway - what does this really change?
I should note that I'm using a Passware product called Office Key.
This crack just takes what has been commercially available for quite some time and moves it into the public arena.
Josh
How many roads must a man walk down? 42.
Is this a dupe? I could swear I've read this one before.
According to Microsoft, the password protection feature on Word is not intended to be secure, but should be regarded as a means to protect documents against accidental modification. I use Word and don't ever recall being advised of this, but then I suppose the EULA does warn users never to actually rely on the software for anything important.
I never expected the protection in Word to be anything special, but sometimes (as shown here by Dell) it's better to have no security than false security because that way you take greater care.
But for those of you who never RTA, here is what was the highlight for me:
Aide-toi, le Ciel t'aidera - Jeanne D'Arc.
I swear, you guys gave me a quote of $6.35 for a new Latitude.
If I recall, openoffice/staroffice can open "encrypted" Word and Excel documents without the requirement of a password. I know this used to work for older versions...
-- Minds are like parachutes... they work best when open.
Come to think of it, I can't think of a real position where this could be a problem. What would someone do, host protected
Etiquette is etiquette. He kills his mother but he can't wear grey trousers.
As SF.com is located in the US, isn't this exactly something covered under the DMCA: publishing a method to circumvent a protect mechanism.
In that case, what are the chances of them getting into trouble?
If an experiment works, something has gone wrong.
Another case of "if you build it I'll break it"
Anything built by man can be cracked by man.
DRM is useless bloatware.
Passwords can use a one way function.
Take the source string, do a bunch of 'stuff' to it, stuff that isn't easy to undo.
You can throw out some data too.
You end up with a new string, but since you threw out some information, you end up unable to reverse it.
Even if you know the end result, and the formula, you can't guess the password. You'd have to brute force it.
With slow computers, this was a very good obstacle. Now we use fancier algorithms, and it is still okay.
I'm not a math guy, go read crypto books if you want the 'real' explanation
I've been playing around with some digital signatures solutions (like the one from arx.com) to deal with issues like these - documents that must be "signed" and verified beyond "reasonable doubt".
What it comes down to isn't necessarily a "Microsoft Word" problem - it's an issue with verifying that data has its integrity. Probably doing an MD5/SHA1 hash on all documents and attaching that with the document would be good enough - which means you could just use text files instead.
52 Weeks, 52 Religions with John Hummel
Without some type of private/public digital signature system, you're going to see problems like this. Don't trust passwords on supposed read only documents as a general rule.
The sooner business people understand these things, the sooner that we'll all see the benefits of a standardized, omnipresent public key infrastructure. Make sure to educate the nontechnical people in your office so that they demand better security for their data.
Why are you letting these clowns ruin our country?
The real solution is a digital signature. Anyone to whom that is not obvious shouldn't be putting security measures in commercial products.
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
If you use this feature and expect it to be secure in my opinion you're just asking for trouble. Of course this is M$'s fault, but really! Is this a surprise to anyone. I mean, anything can be hacked in time, but a password-protected word document? I've forgotten passwords myself in the past and decrypted the file in about a half-hour, and I'm hardly what you'd call a l33t d00d! I mean FFS! It's a word processor. Two answers to this. A) Don't let anyone but you have access to the file. Protect your PC and it's harddrive. B) Use something like steganos, or something better to securely encrypt your files. Don't trust in the MS. Anyway, everyone should be using AbiWord.
Sign the FSF's Anti-DMCA petit
The fact that it can't determine your actual password is a good thing. Not for the security of that particular document, obviously, but for the security of other things you may have used the same password for.
I work with Dell for our workstation and laptop purchases and not once in the last 3 years have they sent me a quote in a Word document.
They have a system that links the quote with your customer ID and gets generated as an HTML file which gets emailed to you. All automagically.
To whom ever that thought they could change a word document quote and expect to get that price, I got some beach front property to sell you in Kansas. Silly fool.
It's old news -- that's why Microsoft prefers PDF for the really important stuff.
that I noticed my customer was a 12 foot tall monster from the crustacious period! He looked me right in the eye and said, 'My quote for the dell says about Tree-Fitty!' and I said GOD DAMN YOU LOCHNESS MONSTER!
2003-11-27, 10:30 UTC Microsoft notified to: secure microsoft com
2003-11-27 confirmed receipt from: secure microsoft com
2003-12-03 Note from Microsoft, Form protection "is not intended as a full-proof protection for tampering or spoofing, this is merely a functionality to prevent accidental changes of a document", request additional time to update Microsoft Knowledge Base article.
Targetting beginning of January 2004 for release of this advisory.
from: "Magnus"
2003-12-08 Microsoft has already released the KB article (or added a warning to an existing article). Read the KB article at http://support.microsoft.com/?id=822924
from: "Magnus"
bad sig...no donut.
OK, I'm not saying that Microsoft's totally without guilt here but just how far do people think they need to go with regards to securing passworded files? 48-bit encryption? 128-bit? 160-bit with triple DES? At what stage does the encryption become overkill?
And what about the consequences of selling Office (or even emailing a file) around the world with such strong encryption? It wasn't that long ago that the 128-bit encryption version of Internet Explorer couldn't be downloaded by anyone outside the US (even people in countries such as the UK) because that key length was longer than US export laws allowed at that time. So where do you draw the line between too weak (to be of any use to anyone at all) and too strong (to be of use to anyone who needs to deal with anyone based outside the US)?
"Accept that some days you are the pigeon, and some days you are the statue." - David Brent, Wernham Hogg
Was this ever really meant to be really truly secure? "security" features like that have always been lame at best and equivalent to luggage locks. These passwords have always been susceptible to brute force attacks. Anyone really serious about keeping documents safe puts them into a source control program. There are many ways to pick at MS's security, this is not one of them. But if you are trusting these measures for really secure documents, I highly suggest you get your valuables out of the pink plastic safe you won at the county fair last year.
To: BugTraq /tdk :-)
Subject: Microsoft Word Protection Bypass
Date: Jan 2 2004 10:51AM
Author: Thorsten Delbrouck-Konetzko
Hi all,
Microsoft Word provides an option to protect "forms" by password. This is
used to ensure that unauthorized users cannot manipulate the contents of
documents except within specially designed "form" areas. This feature is
also often used to protect documents which do not even have form areas
(quotations/offers etc.).
This form protection can easily be removed without any additional tools
(apart from a hex-editor).
Please find the full advisory attached.
best regards,
Thorsten Delbrouck
Chief Information Officer
Guardeonic Solutions AG
Rosenheimer Str. 116
D-81669 Munich
Security Advisory #01-2004
Advisory Name: Microsoft Word Form Protection Bypass
Release Date: 2004-01-02
Affected Product: Microsoft Word
Platform: Microsoft Windows, probably Apple Mac OS
Version: tested on 2000, 2002 (XP), 2003,probably other versions vulnerable as well
Severity:Document ("Form") protection can be easily removed
Author:Thorsten Delbrouck
Vendor Communication:2003-11-27, 10:30 UTC Microsoft notified to: secure microsoft com
2003-11-27 confirmed receipt
from: secure microsoft com
2003-12-03 Note from Microsoft, Form
protection "is not intended as a full-proof protection for tampering or spoofing, this is
merely a functionality to prevent accidental
changes of a document", request additional
time to update Microsoft Knowledge Base
article. Targetting beginning of January 2004 for release of this advisory.
from: "Magnus"
2003-12-08 Microsoft has already released the KB article (or added a warning to an existing article). Read the KB article at http://support.microsoft.com/?id=822924
from: "Magnus"
Overview:
Word provides an option to protect "forms" by password. This is used
to ensure that unauthorized users can not manipulate the contents of
documents except within specially designed "form" areas. This feature
is also often used to protect documents which do not even have form
areas (quotations/offers etc.).
(Word users will find this option on the "Tools" menu, entry "Protection", select "Forms" there and provide a password)If a Word document is protected" by this mechanism, users cannot select parts of the text or place the cursor ithin the text thus they cannot make any changes to the document.
Description:
When saving protected Word-documents as html-files, Word adds a
"checksum" of the password (enclosed in a proprietary tag) to the
code. The checksum format looks somewhat like CRC32 but currently
there are no further details available. The same checksum can be
found within the original Word document (hexadecimal view). If this
"checksum" is replaced by 0x00000000 the password equals an empty
string.
Example:
1.) Open a protected document in MS Word
2.) Save as "Web Page (*.htm; *.html)", close Word
3.) Open html-document in any Text-Editor
4.) Search "" tag, the line reads something like that: ABCDEF01
5.) keep the "password" in mind
6.) Open original document (.doc) with any hex-editor
7.) search for hex-values of the password (reverse order!)
8.) Overwrite all 4 double-bytes with 0x00, Save, Close
9.) Open document with MS Word, Select "Tools / Unprotect Document"
(password is blank)
Variation:
If the 8 checksum bytes are replaced with the checksum of a known
password it should be fairly easy to unprotect the document, make any
necessary changes, save, close and reset the password to the original
(unknown!) password by simply restoring the original values. Document
changed without even knowing the password. Nasty.
(Note: Take care to get file properties (author, organisation,
date/time etc.) right.)
Solution:
No solution is currently available. Do not rely on the "Protect
Forms" mechanism to protect a Word document against changes.
Credits:
Magnus from the Microsoft Security Response Center for his fast
responses and for showing a decent sense of humour.
If the program claims that you can lock a document against modification, then shouldn't it provide verification of that? Or does it believe in its infallability.
I know MS word includes signatures, why wouldn't a signature be an automatic feature on a locked document???
shame.
This could become a very large legal problem for Word users that rely on this type of protection to (legally) prove that files have not been tampered with (think FDA submissions for pharmacuticals).
I see this being a larger problem in the future, when MS Office DRM is used on most files assuming that these files will follow the orderes encoded into their DRM. Imagine a file that is supposed to self-destruct in 10 months as part of a document retention lifecycle. Two years from now, a tape backup of that file is subpoenad and the DRM is hacked so that the file is openable, leaving said company liable for its contents previously thought destroyed.
I don't mean to rag on Microsoft or its protection schemes, more on those who use these weak means as a method of security in their infrastructure. A good server-based file protection model will always trump a good in-file-based protection model.
__________
Love conquers all... except CANCER
If you don't want your document to be changed by others, why don't you crypto-sign it?
Its not specific to any specific document format or type and requires no extra features/code on the behalf of every program. Ofcourse "Password-protecting yadda yadda yadda" sure sounds good on a feature list of a word processor, even if completely useless.
Microsoft pointed to this Knowledge Base article. Choice quote: "Not all features that are found on the Security tab are designed to help make your documents and files more secure."
My understanding of the hack is this: it is possible to unlock a word document or form (i.e., make read-only parts writeable), modify it, and then re-lock it with the original password, without ever having to know what the original password is.
Which then raises the question: in the hashing algorithm Microsoft is using to scramble the password, why the hell aren't they adding in some cryptographic salt?. If they had made the scrambled password (which is leaked when a locked document is saved as HTML) depend not only on the cleartext password, but also on the read-only parts of the document, then they wouldn't have this problem: a hacked document re-locked with the same scrambled password would have a different salt, and therefore a different cleartext password. D'oh!
Tubal-Cain smokes the white owl.
The page is titled: "Overview of Office Features That Are Intended to Enable Collaboration and That Are Not Intended to Increase Security", and reeks of hindsight. Microsoft notes that these features were never intended to increase security, but were designed to encourage collaboration.
But on the other hand, they also say:
"Information About Strong Passwords To reduce the chances of someone guessing your password, use only strong passwords.
For a password to be a strong password, it should meet all the following criteria:
* Be at least seven characters long. Longer passwords are more secure.
"...etc.
Why would users be encouraged to use strong passwords, not easily guessed by malicious users etc, when they were just intended to avoid accidental modifications? The document is clearly a lame attempt my M$ to coverup a serious vulnerability by suggesting that the feature was not designed to provide security. However, I bet they would not have hesitated to tout it as a "security feature" in Microsoft Word, had the vulnerability not been found.
An Indian-American Hindu committed to non-violent thought/speech/action alarmed by the global explosion of radical Islam
This is excellent news. The more Microsoft continues to prove itself as market leaders in security the more copies of Windows XP SP2 they can sell.;)
...
nick
Electronic Music Made Using Linux http://soundcloud.com/polyp
I've modified "protected" Word documents by opening them in Notepad and scrolling through the last few lines until I find a string of plain text that looks like a password (i.e. isn't a username or Word setting). Although this takes a bit more time for the searching, there's no need to modify the password at all.
I would like to see this hack become a feature in OpenOffice.
All password protection that Microsoft use in their products is an eternal source of inconvenience. There was at least three cases in last five years when we had to use (il)legal cracking tools to recover _our own_ data in MS Access and MS Words when employee forgot password.
You're new here aren't you?
/.
Welcome to
First of all, if you read the article, you will understand that Microsoft has not been advertising these "Word document passwords" as true security mechanisms. Microsoft has been pushing its new DRM Features in Office 2003 as the Microsoft-approved method to secure Office documents.
In fact, I doubt Microsoft really put much effort into making these document-modification passwords all that secure. They have been around for quite some time, and I doubt they have changed much or improved much over the years. I don't know anyone who was relying on these document passwords for their security, and Microsoft did not advertise this as a great feature of Word. In fact, the bug itself is limited in scope to protecting Word FORMS from being modified.
In any case, the new DRM features in Office 2003 are much more sophisticated and will no doubt be much more difficult to crack. THESE are the security features that Microsoft is pushing today, and if you really want to lambast Microsoft Security, then you must point out a way to subvert these newer technologies that Microsoft is actually pushing.
It would be very big news indeed if someone could succeed in copying an Outlook 2003 email marked with a "Do Not Forward" permissions flag. Indeed, if someone could even READ such an email on an unauthorized email client, Microsoft's newest security policies would be questionable. Until then, I'm not convinced this is anything more than FUD trying to convince people that Office is inherently insecure.
"A ZDNet UK article says Dell uses password protected Word files to send quotes, which could make for a messy legal battle."
ZDNet overreats. All Dell has to do is digitally sign the word files with gpg. Better yet, screw Word files and distribute digitally signed PDF quotes.
Word files are meant to be edited. This stupid password security is a bolt on hack to try to make Word files do something they were never intended to be in the first place: secure electronic documents. There are, and have been for a long time, much better solutions.
A while back I read an article on the legality of manually changing the HTML form used by some shopping cart software. Is it legal to change the price of a plasma screen TV to $250 instead of $5000? Could you force the seller to honor the adjusted price?
The answer, surprisingly, is that the "hacker" had an excellent chance of winning in court. Quotes are offers and subject to negotiation. The burden is on the offerer to verify that the counteroffer is acceptable - they are always free to reject any counteroffer and insist on the original price. The company can either pay to have somebody check the prices in counteroffers (or to have somebody automate that check), or it can absorb the loss when it automatically accepts such counteroffers.
For every complex problem there is an answer that is clear, simple, and wrong. -- H L Mencken
Today I want to show how you may load some xls-file that is password-protected, and how to save xls into another file but without protection.Just replace there file names and password Not sure if it works on the latest version. Office Automation - coming soon to a worm near you.
This came up at work. What happens if: You send out a contract as a Word doc email attachment. Customer changes the language of the contract, signs it, prints it, then mails it back. We could easily sign that without noticing the difference.
We decided to send out digitally signed PDFs instead.
pkzip files have always had genuine data encryption (the sort that isn't viewable with a hex editor), but that encryption has traditionally been quite weak. I'm unsure if the new schemes are any better, but I doubt many people use that aspect of pkzip files anyway.
Ita erat quando hic adveni.
I'm sure that some people here are laughing at Microsoft for its "lax security." Of course if you really wanted to protect a Word document you could use Office 2003's built-in encryption features, which rely on Windows Rights Management. Yet the people who criticize Microsoft for Word's "security hole" are also the most vocal opponents to anything having to do with trusted computing, including Windows Rights Management. You can't have it both ways, you know. You can either accept that Microsoft's WRM already has a solution to this issue, or you decide that the additional security that WRM provides isn't worth the imagined "privacy and freedom" implications. But don't say that MS should make their file formats more secure while at the same time dismissing WRM.
I helped a family member install a washer/dryer set. It took 220v/60hz and he hadn't installed the plug onto the bare wires.
We asked my dear cousin if the breaker was set to "off," asked her to double check, and then went to work. I went to work and accidentally bumped the wires, causing a huge arc about 2 inches in front of my eyes.
I was lucky to live, folks. I'm not sure who the bigger fool was, me or my cousin. The leson is that a wire isn't dead until you have personally checked it, and checked it again. Even then you have to be careful.
I'm pretty new to high voltage electronics and information security, but I have learned a lesson.
It seems to me that even if you use this Word feature, and know what it does, you can't count on your documents being secured. Another ignoramus will come along and screw it up and you won't know it. I really despise half solutions. They are as useful as almost making jump over the Grand Canyon.
Now, we all know what the information security equivalent to lockout/tagout is, right?
Done venting now, thanks.
Why do I have this? I don't smoke.
Myself and others have tried to reproduce the bypass and cannot. I have created several forms documents as well as found existing ones to try it on. Whenever I save as HTML, the w:UnprotectPassword tag is not present. Initially I had problems with the HTML compatibility settings, which I got worked out, but even after using every logical combination of settings I still do not get the tag. I have tried different methods of protecting the document, still no password hash in the HTML.
I can easily bypass the document protection, but not in a way that is not noticible.
What am I missing or has anyone successfully reproduced?
KB article 189126, two clicks away from the article referenced in the parent, offers this nugget of wisdom:
The password-protection systems built into Microsoft programs are designed to be unbreakable; there would be no point in including a password-protection system that could be broken.
Well, then, Microsoft, why is there a breakable password system in your product?!
Too late to be known as Bush the First, he's sure to be known as Bush the Worst.
XOR against a passphrase is weak.
XOR against a repeating secure (irreversible) hash of the password is technically weak but in practice very strong unless the message is dozens of times longer than the hash.
XOR against a successive concatination of secure hashes is strong, fast, and simple. There is no reason to believe 3DES is any stronger. Plus, it's the same algorithm for encrypting and decrypting. Pseudocode:
> IAAPN (I Am A Punctuation Nazi): the headline should read "Microsoft Word Forms' Passwords Cracked" or "Microsoft Word Forms's Passwords Cracked".
./, but true.
Apparently IKEGBTYD (I Know English Grammar Better than You Do): Wrong. Nouns being used in a partitive or atttributive sense are not possessives and do not require apostrophe + s. (You say "C compiler" and "dog food", and not "C's compiler" and "dog's food", right?)
The headline is correct. Hard to believe since this is
Il n'y a pas de Planet B.
Why anyone would choose to use a Word document for the purpose Dell used it is completely beyond me. Are they so brainwashed over there that there was no exploration of the alternatives? Particularly in view of the fact that the app vendor (M$) specifically does not promote the use of that feature for securitys sake.
Really Dell, STFU, your precious relationship with Microsoft does not preclude using your brains when making software selections for sensitive processes like binding quotes...
On the plus side, I'm sure I've got a Dell quote somewhere in the office... Hmmm, laptop for $15 anyone?
"Talk minus action equals nothing" - Joey Shithead, D.O.A.
"Talk minus action equals
Clearly the article was a joke. The Credits at the end of it give it away: "Magnus from the Microsoft Security Response Center for his fast responses and for showing a decent sense of humour. :-)"
A one-way function is simply some function which is not one-to-one. For example, consider the length function L which maps words to integers, e.g. L("bob")=3, L("A")=1.
Think this one through. The algorithms used to sign PGP/GPG messages are one way. The reason being is that it's hard to come up with something else that maps to the same value.
Using your length function example, considering the two e-mails from Alice
"I love Bob"
"I hate Bob"
Would both parse to 1 4 3. Which means Eve could flip Alice's feelings for Bob, without invalidating the signature.
That, my friend, is a crappy 'one-way' function. So crappy, that's it's not really one-way.
The "multiple inputs give the same output" thing just means it's non-linear. And all that that implies.
- Last document editor's name, initials,
and company
- Computer name last edited on
- Path (incl server
name) of last save (Remember all those hacks that require the
miscreant to know specific file path & names?)
- Previous
editor's names
- Number of revisions and versions
- Template
name and path
- Any hidden text
- Comments
This is why you distill DOC to PDF before passing it around or posting it on the web, so none of the aforementioned information is inadvertently released. Yes, someone can still change it, but that's what digital signatures are for.Side note: PDF Passwords ARE TRIVIAL to break. Don't try to protect your PDFs from printing/copying/etc. with the built-in "security." It takes about 15 seconds with publicly-available software to crack any PDF.
Yeah, right.