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Security Experts Rebut The Guardian's Report That Claimed WhatsApp Has a Backdoor (gizmodo.com)
William Turton, writing for Gizmodo: This morning, the Guardian published a story with an alarming headline: "WhatsApp backdoor allows snooping on encrypted messages." If true, this would have massive implications for the security and privacy of WhatsApp's one-billion-plus users. Fortunately, there's no backdoor in WhatsApp, and according to Alec Muffett, an experienced security researcher who spoke to Gizmodo, the Guardian's story is a "major league fuckwittage." [...] Fredric Jacobs, who was the iOS developer at Open Whisper Systems, the collective that designed and maintains the Signal encryption protocol, and who most recently worked at Apple, said, "Nothing new. Of course, if you don't verify keys Signal/WhatsApp/... can man-in-the-middle your communications." "I characterize the threat posed by such reportage as being fear and uncertainty and doubt on an 'anti-vaccination' scale," Muffett, who previously worked on Facebook's engineering security infrastructure team, told Gizmodo. "It is not a bug, it is working as designed and someone is saying it's a 'flaw' and pretending it is earth shattering when in fact it is ignorable." The supposed "backdoor" the Guardian is describing is actually a feature working as intended, and it would require significant collaboration with Facebook to be able to snoop on and intercept someone's encrypted messages, something the company is extremely unlikely to do. "There's a feature in WhatsApp that -- when you swap phones, get a new phone, factory reset, whatever -- when you install WhatsApp freshly on the new phone and continue a conversation, the encryption keys get re-negotiated to accommodate the new phone," Muffett told Gizmodo. Other security experts and journalists have also criticized The Guardian's story.
It would be nice if The Guardian produced a list for the average person of the most popular software that has known backdoors like Skype, so people can see how compromised they are under pretext of "tackling terrorism".
Take Nobody's Word For It.
Well, apparently the President Elect of the USA believes the anti-vaccination idea, so...soon it will move on from "fear and doubt" into "official policy".
Well, first off, I'm going to be a little suspicious of experts who find fuckwittage in their dictionary, when a stupid cacahead reference will do. I dunno that taking a temper tantrum reassures me all that much.
My guideline is that if it is allowed, it is visible to someone who wants to see it badly enough.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
All those "ignorable" things are the reason why security eventually fails.
The supposed "backdoor" the Guardian is describing is actually a feature working as intended, and it would require significant collaboration with Facebook to be able to snoop on and intercept someone's encrypted messages, something the company is extremely unlikely to do
That sounds like a back door to me. Who trusts facebook anyway?
The Guardian has created a big name for itself for the massive scoops it has delivered.
Sometimes this leads to the unrealistic expectation that the scoops can keep being manufactured at a steady rate. Trying too hard much?
Happiness in intelligent people is the rarest thing I know.
Ernest Hemingway
Muffet is saying it's "major league fuckwittage", while acknowledging that the main point is true: Facebook could in fact intercept messages.
Jacobs says "well duh, if you send a message without verifying keys" - and Whatsapp does just that, automatically resends the message before you have a chance to verify the key.
Currently, since July, I am employed by nobody. And loving it.
Previously to that I worked at Facebook, built their Tor onion, and build Facebook Messenger E2E crypto.
So, I'm competent to comment, and beholden to nobody :-P
perl -nle 'setpwent;crypt($_,$c)eq$c&&print"$u=$_"while($u,
First, this is really old news picked up by the Guardian: https://tobi.rocks/2016/04/wha... That's almost a year old! Second, this is not the biggest security issue IMHO: default WhatsApp behaviour is to backup all your messages unencrypted to Google Drive, therefore, if a government wants to read your messages, they'll just ask Google! (the content is inaccessible by you, but not to them! https://developers.google.com/... )
"The supposed "backdoor" the Guardian is describing is actually a feature working as intended, and it would require significant collaboration with Facebook to be able to snoop on and intercept someone's encrypted messages, something the company is extremely unlikely to do."
A backdoor that requires Facebook's help to snoop is still a backdoor, is it not?
If it's no big deal, where's the option to disable this autorenegotiation of keys, assuming that I'm not fussed about whether my messages migrate when I update my handset, but am fussed about Facebook having the technical means to give a copy of my supposedly secure messages to any random phone that their system authenticates?
The Whatsapp client is proprietary and closed source.
It should be assumed to be compromised regardless of what anyone says about it.
A government is a body of people notably ungoverned - AC
He is missing the point.
The article is not speaking about an encryption flaw or anything like that, but about a backdoor - a feature that allows Facebook, without any code changes on your device or other intrusion - to eavesdrop on any conversation you are having.
A good encryption would be impenetrable even to the vendor. It should not allow the keys to be changed underneath you. It should not warn you afterwards about this fact, and only if you have a special option enabled, but it should tell you before it does a key change, and require your consent.
Assorted stuff I do sometimes: Lemuria.org
There is a problem in my opinion and denial won't get it fixed. Sure you need to renegotiate keys with a new device but it should not happen automagically without your knowledge. You should have to do it manually and it should not be done for you based on an assumption and all your messages be resent with the new keys.
Whatsapp's defaults do not prevent MiTM and do not even warn you something's afoot.
That's doubleplus bad.
I think we can leave it at that without the drama.
Why should we believe Facebook won't invest the time in being able to exploit this for eavesdropping? They already lied to regulators about not sharing data between itself and WhatsApp. It sounds extraordinarily naive to think they won't try that use this as a backdoor.
Because there are way better ways to drill holes in E2E than this, when in fact you own the codebase.
perl -nle 'setpwent;crypt($_,$c)eq$c&&print"$u=$_"while($u,
Some disclaimer:
I have moderate IT Security experience. I'm admittedly not the ITSec convention-going type, but I've developed for solid security, done successful penetration testing on people's code and the likes... From the guardian's article, and from my POV, the major issue here is one of wording: a Backdoor is a feature, one intentionally added by developers and hidden from the end user-facing stuff such as UI and (R)TFM. This is definitely not a backdoor - it looks like a flaw, probably associated with different use cases of whatsapp vs the original API, considering it happens on verbose conditions, and it surely seems tricky to replicate without very explicit user behavior. Apparently even a change in defaults by whatsapp can solve this.
Now for the real issue:
How can anyone even start arguing about an article's guilt on this or Whatsapp intentions without tackling the subject that: every closed source app claiming privacy (such as whatsapp), however you paint it, can never do so as guaranteed without being open source. There is one way, and one way only, that privacy can be achieved without having to trust on privacy policies, disclosures, public legal action or even secretive court orders and it is to open source the damn thing and providing a way of building that outputs the same without the branding (think Chromium or the Mozilla suite in Debian).
Here's the deal: Whatsapp states it uses the Whisper API but they might as well not use it. Whisper and Signal might state they collaborate and trusts they do use it, but who is to say they aren't being paid for this, lying or even chain-trusting blindly in Whatsapp statements of use? Oh wait, so there's a legal binding document saying Whatsapp actually does this... BIG DEAL. There are also constitutions being RAPED EVERY DAY by US, Chinese, Russian, (every country?) security services.
Snowden advises on using Signal for two essential reasons that cannot be taken apart:
1. he has access to the shyt going on inside and...
2. he actually understands that shyt.
Number one is the big deal here, and number 2 is the reason he publicly admits his support for Signal - people trust his technical judgement. Granted, no.1 won't make much sense to 99% of the world at which point you have to start trusting on someone's technical ability, reputation and honor, and for fuck sake Whatsapp is a commercial application based in the US - they HAVE to lie about such things, they don't even get a choice. Just having no.1 is like placing your neck under the sword of the entire world community. It's a lot better than a feature list, and advert, a legal document, someone's word. it's everybody's word.
This is no conspiration theory, but logic beats trust, and most here, as engineers should be very aware of that. Even the trust in one's own actions isn't fallible - some people lie to themselves, some people don't know better than to believe they have failed at something and will trust blindly on their own ability. But sooner or later everybody finds out we are only as perfects as what we are made of. SHOW ME WHAT YOUR APP IS MADE OF and you will have the right for my complete blind trust (because it just isn't blind anymore). It can even be coded in esperanto (intentional bullshit here). It's the only way it is honestly submitted for scrutiny of your own statements of privacy and security.
a) just check my twitter for proof - and my 4-digit Slashdot ID. :-)
b) i've built a reputation for 25 years, saying such things. Go dig up my USENET from 1991. Hasn't done me any harm that I care about, and it has done me measurable good when people see me commit to a set of values or a proposition with no "if", "and" or "but".
c) at least I'm funny. :-)
perl -nle 'setpwent;crypt($_,$c)eq$c&&print"$u=$_"while($u,
There probably are. Either way, if they really wanted to shutdown this backdoor talk they should change this behavior. Otherwise the only thing we have to go by is a non-binding "promise" from a known liar.
If you don't trust WhatsApp to faithfully regenerate encryption keys, why the hell did you trust them to generate the initial keys in the first place? They could have just given Facebook a key then and let them listen in to your messages at any time. ANY messaging app, no matter how secure, can do this.
This is not a backdoor, it's an inherent vulnerability in all encryption systems. If you don't trust one end of the encryption, it doesn't matter if the keys are only generated once or if they're generated over and over, or if you're notified when they're regenerated or if they just regenerate them on the fly. At any point, an untrustworthy server can simply make a valid key for a third party, and your encryption is compromised.
This is a non-story. You know what 99% of people do in Signal when they get a notification that their encryption key has changed? They hit OK and re-send the message, just like WhatsApp does by default.
It's just like EULA's, nobody pays attention to those damn thigns. WhatsApp just skips the step of asking you to verify the encryption change unless you go into the settings and explicitly tell it to notify you. For most people, that's exactly the appropriate behavior.
Security is mostly a superstition... Avoiding danger is no safer in the long run than outright exposure. - Helen Keller
> by modifying the code
This is news?
perl -nle 'setpwent;crypt($_,$c)eq$c&&print"$u=$_"while($u,
>Not convincing
I'd love you to explain to me an even more plausible way to implement a backdoor than "write one, properly."
perl -nle 'setpwent;crypt($_,$c)eq$c&&print"$u=$_"while($u,
it's owned by Facebook.
My beliefs do not require that you agree with them.
I've criticised a Guardian article, entirely justifiably. As for the underlying issue, it's a design consideration for usability. I actually don't like it, but I respect the choice.
perl -nle 'setpwent;crypt($_,$c)eq$c&&print"$u=$_"while($u,
So your comeback is that corporations would only write super-secure backdoors? That's a joke, right?
Open source is always better than closed source.
I mean, it's not even worth arguing. You have one more vector of insight into what's happening.
Compiled binaries can be corrupted, and you can end up with a compromised compiler, kernel, or even, theoretically, hardware.
Nevertheless, open source software is always more trustworthy (assuming equal stated functionality, of course).
Proprietary, closed source: score zero. You have literally no idea, and no way of investigating. You operate on total faith.
Open source software: score not-zero. You have a chance at achieving security. You operate on as much faith as you feel comfortable with.
A government is a body of people notably ungoverned - AC
>> It is not a bug, it is working as designed ...
Backdoor is working as intended. Nothing to see here. Move on. Yeah right.
He is talking about a legitimate feature in the protocol that has a reason to be here but is turned into a genuine backdoor by the Watsapp application because watsapp does not let the user confirm new keys.
aaaaaaa
Well, if it's open source, it's likely that someone else has done an audit of the code, and even if I haven't looked at each line of code, someone else probably has (if it's popular enough). While it's possible to hide a loophole in popular compilers, I think this is hard to pull off. The government has a lot of resources, but it's also big, slow, and leaky, so I don't think it could pull off a sophisticated compiler loophole without people noticing.
On the other hand, an Windows operating system backdoor is a lot easier to pull off, since it's closed source and controlled by one company. The NSA could put hacks in Windows to capture message buffers from popular messengers, bypassing the whole encryption.
The difference is that we have the opportunity to review free/open software to verify its functionality and that it is working only in our interests.
Should we trust open software? No, but we don't have to trust it. We can verify for ourselves, or pay someone qualified to do it.
Should we trust closed software? Probably not, but what choice do we have.
1) Really, dude, go read my Twitter. I'll post this there.
2) It's not a backdoor. It has an off-switch. It would be a pain to exploit. It would be ugly, obvious and risky to exploit. If such snooping was sought, it would be done better..
https://twitter.com/AlecMuffet...
perl -nle 'setpwent;crypt($_,$c)eq$c&&print"$u=$_"while($u,
My comeback is that corporations which are held to be super-smart-and-sneaky one moment should not be assumed to be bone stupid the next.
perl -nle 'setpwent;crypt($_,$c)eq$c&&print"$u=$_"while($u,
"2) It's not a backdoor."
If facebook received an NSL or warrant, it could trivially trigger this "ugly, obvious, risky" mechanism and read "secure" traffic, with little if any visible sign at the sender / recipient.
It is a backdoor accessible to facebook or people who control it. That's bad enough.
>If facebook received an NSL or warrant, it could trivially trigger this "ugly, obvious, risky" mechanism and read "secure" traffic, with little if any visible sign at the sender / recipient.
(cough/) how about bunches of messages randomly going missing?
kindly go read this: https://whispersystems.org/blo...
perl -nle 'setpwent;crypt($_,$c)eq$c&&print"$u=$_"while($u,
It is downgrading the security. Normally, an attacker would need to steal your key or the receiving end (you and the other person in turns) will get "wrong key, somebody is doing something BAD" warnings.
Whatsapp doesn't do this. Whatsapp displays a message "the remote end has changed its security number[sic!]". But only if you activated it in the settings. Else you get NO HINT AT ALL.
The next point are unsent messages. The report seems to exaggerate there a bit. The problem here: Go offline, type some messages. Go online, they are sent. Before you have the chance to see the "security number changed" message, which may have you prevented from sending the messages.
The problem is there but doesn't happen often, because its likely you see the message soon (if you do not ignore such messages).
I did not test it, but it may be, that you get the message only after the next message you sent, even when you're online. Which is another trap, if you really need security for every message.
So you built a Tor Onion for a site that requires a login?? Isn't that kind of a major oxymoron?
Schneier mentions this vulnerability as a real threat on his blog. https://www.schneier.com/blog/... Did he actually endorse anything that says it isn't? (The link on the main page of slashdot.org claims he did.)