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“Someone was typing in a URL and WhatsApp was fetching it off my server”

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Re: “Someone was typing in a URL and WhatsApp was fetching it off my server”

#21

E: Disregard. Whatsapp is doing exactly what they should be doing. Telegram seems to proxy the requests. Why is no one saying anything about end to end crypto? Whatsapp shouldn't be able to see my messages, isn't that what they say themselves?

i guess then they loose the preview feature..

Re: “Someone was typing in a URL and WhatsApp was fetching it off my server”

#22

In order to produce the link preview, probably. As far as why it's character by character, I don't know, but that doesn't seem very sinister to me. Checking URLs letter by letter is sloppy, especially if you're not even trying to do auto completion, but it doesn't reveal any more information than a complete url could. Anyway, I would think they are expecting people to paste URLs in, not type them. I've written code t…

It's not sinister so much as that Whatsapp is sending the requests directly from the user's phone (not through a proxy, etc) which is exposing the end user's IP address and full user agent string to the website hosting the page. This information could be used to identify the end user which goes against Whatsapp's whole "Privacy and Security is in our DNA" thing. (https://www.whatsapp.com/security/)

See this tweet for the info exposed: https://twitter.com/0xjomo/status/874585822158352384

Re: “Someone was typing in a URL and WhatsApp was fetching it off my server”

#23

E: Disregard. Whatsapp is doing exactly what they should be doing. Telegram seems to proxy the requests. Why is no one saying anything about end to end crypto? Whatsapp shouldn't be able to see my messages, isn't that what they say themselves?

The app obviously can see the messages, this happens on the clients.

Yeah, just tested. I assumed Whatsapp would fetch serverside but no and thus expose client IPs.

Telegram seems to proxy the requests.

So Whatsapp wins with crypto here.

Re: “Someone was typing in a URL and WhatsApp was fetching it off my server”

#24

One aspect is the lack of debounce, but also revealing the endusers ip and user agent. They could proxy external link requests via whatsapp servers without breaking end to end encryption. wonder what iMessage does ?!

Could you explain how that would work? Right now they seem to be doing it client side thus not ever seeing the URL themselves. If they were to have a proxy said proxy would need to know the URL to fetch. Is there some alternative solution?

Re: “Someone was typing in a URL and WhatsApp was fetching it off my server”

#25
Did you all know that chrome does this too? May sound obvious but I always had assumed that nothing is sent until you press enter for some reason (yeah I know, search prediction would be impossible without that). But one day I was type in a path on a test URL and noticing my server getting hit on - every single letter.

Re: “Someone was typing in a URL and WhatsApp was fetching it off my server”

#26

One aspect is the lack of debounce, but also revealing the endusers ip and user agent. They could proxy external link requests via whatsapp servers without breaking end to end encryption. wonder what iMessage does ?!

> They could proxy external link requests via whatsapp servers without breaking end to end encryption.

What good is E2E if you are going to send the plaintext home anyway? Doing these requests on the device is stupid, but proxying them through FB servers would border on malicious.

Re: “Someone was typing in a URL and WhatsApp was fetching it off my server”

#27

Did you all know that chrome does this too? May sound obvious but I always had assumed that nothing is sent until you press enter for some reason (yeah I know, search prediction would be impossible without that). But one day I was type in a path on a test URL and noticing my server getting hit on - every single letter.

Yes, I did know that. The difference is WhatsApp is selling encrypted-onboard privacy. Which is now, prima facie, a lie.

Facebook has literally told courts they can't decrypt WhatApp traffic. I wonder if that court case in Brazil is still pending.

By comparison, no one ever said "There's no way Google could read my search terms".

A more accurate comparison would be regarding Allo.

Re: “Someone was typing in a URL and WhatsApp was fetching it off my server”

#28
Does anyone else really not like autocomplete everywhere constantly sending beacons and data about what you're typing?

I realized I accidentally had a password copied to my clipboard and I pasted into into my address bar. Well great, I didn't push enter, didn't search for the password, but now I have to change my password because it was sent to google because autocomplete.

It's very frustrating because often times people are not aware they are exposing sensitive information via URLs for internal resources.

Re: “Someone was typing in a URL and WhatsApp was fetching it off my server”

#29

Did you all know that chrome does this too? May sound obvious but I always had assumed that nothing is sent until you press enter for some reason (yeah I know, search prediction would be impossible without that). But one day I was type in a path on a test URL and noticing my server getting hit on - every single letter.

Yes, I did know that. The difference is WhatsApp is selling encrypted-onboard privacy. Which is now, prima facie, a lie. Facebook has literally told courts they can't decrypt WhatApp traffic. I wonder if that court case in Brazil is still pending. By comparison, no one ever said "There's no way Google could read my search terms". A more accurate comparison would be regarding Allo.

Oh, cool yeah just pointing it out!

Yeah this is a much bigger deal, for sure, as it's a messaging app - just pointing out similar case in a different application.

Re: “Someone was typing in a URL and WhatsApp was fetching it off my server”

#30

Did you all know that chrome does this too? May sound obvious but I always had assumed that nothing is sent until you press enter for some reason (yeah I know, search prediction would be impossible without that). But one day I was type in a path on a test URL and noticing my server getting hit on - every single letter.

Yes, Chrome does it as well, but I expect that as it's a web browser. I know the tradeoffs when browsing the web and expect that my requests will be visible across the Internet. That's just how web browsing works.

However, WhatsApp is selling a solution that is meant to provide privacy. When I write a URL in an SMS, my phone does not try to preemptively retrieve it to display a preview. WhatsApp may be encrypting the message, but it's identifying me to a server while I'm composing it, which is enough to completely destroy any level of privacy or anonymity that I would expect.

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