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146

Let's hope and assume that facebook stores only hashes of current password (and potentially previous passwords). Here is what they can do: user sets first password to "first" and fb stores hash("first"). later on, users resets password and is asked to provide new password "First2" facebook can generate bunch of passwords (similar to the new one): ...


89

So, yes, they appear to have a deal with the Telecommunication Providers in different Countries. Well that's ONE explanation. Another one that I like better is simply that they have all their users' contact lists, thanks to their mobile application which no doubt reads everything and sends it back to their headquarters. All they have to do after you ...


35

This is simply Facebook trying to provide a better user experience for those users who may have Caps Lock enabled, or who's devices automatically capitalize the first letter of the password. I don't think there any any cookies per your question. It is likely that the password hashing and storage is as standard as you would expect. The alternate passwords ...


19

Repeat the same process, but use a new prepaid phone number. If they can still guess who you are then it is freaky. If not, then it is probably your friends' contact lists which have been sucked up into Facebook (not so freaky, just regular FB creepy). It would be an interesting exercise to try the same, but with your work number and see what kind of ...


17

I wouldn't know if they do (don't even use Facebook), but it's also possible that they use Hardware Security Modules (HSM) for their cryptoprocessing that don't store hashed passwords but merely reversibly encrypt them. With the volume of authorization requests they have to deal with, this would make perfect sense, as it's orders of magnitude faster than ...


14

You are correct. App secret should be secret and should not be easily obtained by reverse engineering your client code. Facebook uses OAuth so everything I say here also applies to all the applications that use OAuth to authorize and authenticate. The app secret authenticates your client to facebook. Just like a username/password authenticates a user to a ...


13

There's only one correct answer to this. Nobody knows (except Facebook). Facebook could store your facebook password in plaintext, but there also might be some scheme that uses fuzzy hashes or pre-computed hashes of similar passwords. There is really no way of knowing unless we were to break into facebook and audit all of their assets.


12

Here is what using Tor to access an ordinary, non-onion facebook URL looks like: You -> Tor... -> facebook.com Now both of those links (from you to Tor and from Tor to facebook.com) happen on the open internet, so an attacker might watch packets flowing across those links like this: You -> (attacker) -> Tor... -> (attacker) -> ...


11

Visiting the .onion address never leaves the Tor network. Going to facebook.com over Tor exits the network and goes over the clear-net. That clear-net hop allows for an active attacker to get into your traffic. Now, your Facebook traffic is probably SSLed, right? If so, it doesn't matter much, but there's certainly more risk than not exiting the network ...


9

From what I can tell from that article it was an error with the Facebook "Connect" API. This is the button on a site that says "Log in with Facebook". It is just a link the site owner puts on the page. When the user clicks it, you are redirected to Facebook's server. The site owners have no control over what happens after this. It doesn't "bypass ...


9

Edit: Facebook now use HSTS, so both question and answer and now incorrect. Because using HTTPS for Facebook is optional. If you look in "Account Settings" and "Security Settings" there is an option for "Secure browsing". It has defaulted to on since July 2013 but you still have the option to turn it off. If they used HSTS then when you turned off "Secure ...


9

As you guessed, Facebook uses HTTPS, what that means is that requests to Facebook.com regardless of whether they are GET or POST requests are not sent over HTTP, instead they are sent over HTTPS in an encrypted form which the 'http' filter in Wireshark wont be able to display as regular HTTP requests. If you want to view the encrypted HTTPS traffic including ...


8

Directly, no. Indirectly, it's possible. One way: Have a web server, whose access log you control, up and running. Send your chat partner a unique hyperlink pointing to that web server, have them click the link. For example: http://yourdomain.com/JohnDoe.html (the web page does not have to exist, throwing a 404 is fine). Check your web server's access log ...


7

Rather than logging in to accounts they control, I expect voter fraud would be done by clickjacking or CSRF, harnessing the social viral power of Facebook to attract unwitting accomplices. With the prevalence lately of images on Facebook that claim that you can obtain a PS4 simply by "liking" and "sharing" an image and the sheer numbers of people who do so, ...


7

Facebook chat is running on XMPP protocol. It is decentralised, but not P2P. It is similar to email - there is no central server, but lots of domain servers talking to each other and taking care of their clients. I doubt that it would be possible to get IP address from XMPP.


7

Summary: HSTS is coming, but the site has some hurdles related to protecting user information such as not telling a website who you are when you click on a link. Explanation of that particular issue: https://www.facebook.com/notes/facebook-engineering/protecting-privacy-with-referrers/392382738919 Firefox is the last major holdout. Here's comment 14 (March ...


7

Technically you can store the access token in your database, and use it for API calls until it expires. It might be more trouble than its worth, though. For one thing, as Jonathan notes in his comment above, now you have to worry about securing your database and the data in it - these tokens give access to some fairly privileged information about your ...


6

There is absolutely nothing in the OpenID/OAuth authentication methods that guarantees an individual signing-in through them is indeed a unique user. OpenID provides a bit more data in a form of a certificate (user name, email address, and notary) than OAuth's valet key authentication, but that alone isn't enough to prevent voting fraud. Using the word fraud ...


6

Looks like the source domain is legit to me. Here's the whois result for the domain: Registrant: Domain Administrator Facebook, Inc. 1601 Willow Road Menlo Park CA 94025 US domain@fb.com +1.6505434800 Fax: +1.6505434800 Domain Name: facebookmail.com Registrar Name: Markmonitor.com Registrar Whois: whois.markmonitor.com ...


6

Facebook's chat platform utilises the XMPP protocol, which does not disclose the IP address of the client. You are correct in saying that Facebook does not use P2P in their chat. As far as I know, it is not possible to get a facebook IP via web chat of a contact without using social engineering. It may be worth checking whether IP addresses are disclosed ...


6

This has more to do with risk management. You do not have any contract with Facebook or Twitter. So you have a risk that they may change the contents of the JavaScript file without you knowing. This can be malicious or accidental, either way you have no control of this risk. So unless you get a contract with the external party which moves the liability to ...


5

Relax, no need to worry. The email address password+kjdmiikvhppi@facebookmail.com does seem to be authentic. It could be spoofed, but if it were spoofed it would be very likely moved automatically to the Junk or Spam folder. Of course, it is possible that the email is spoofed and it wasn't caught in the spam filter, but I personally think it's not very ...


5

Facebook embeds videos in the News Feed and Timeline by using previous knowledge of the way each site supports embedding videos. That means Facebook tries to "understand" the page to which you're linking, and then attempts to embed it; the user doesn't actually control how the embedding happens, ie. when you see an embedded video on Facebook, you can be sure ...


5

The main method are probably cookies. Facebook will save a small textfile on your computer. Everytime you go to Facebook again it tries to read this file. This way it recognizes when your last login was and probably some other data. At the moment my browser has 13 cookies which come from Facebook. So if Facebook can't read your cookies it thinks that the ...


5

The "verification email" serves three purposes (at least): To deter evil people who automatically create thousands of users, for nefarious purposes (e.g. spamming). With the verification of emails, then such people must at least provide working email addresses, which makes them more traceable than when they do not. Also, the least competent of such wannabe ...


5

Down at the bottom-right corner of the Gmail inbox is a "last account activity" line with a "details" link. You can click on that link to get a list of IP addresses that the account has been accessed from.


4

Contrary to the other answers, actually YES it is possible. However it is not actually so simple, and not exactly as you put it. Instead of directing your victim to a profile, you can send him to your Facebook app. Of course, this app needs to be registered as a valid facebook app, and etc. In the URL to your app, you can submit certain parameters - ...


4

I am not Facebook, but if I were designing their linking system my reasoning for following the links would be this: Shortlinking systems like bit.ly and tinyurl.com are ubiquitous. We need to follow the link to the end in order to scrape content from the page (images, blurb of text) to put in your feed, as well as to correlate you with others that have ...


4

I would suggest sending them an email - that is the full extent of your responsibilities as a good citizen. And then delete your copy of their password. In some jurisdictions you could already be considered to have breached rules or even laws. Don't now go and do something that will be illegal. Don't teach them a lesson; don't hack their facebook account; ...


4

I wouldn't put it past Facebook to "mess up". From the headers, it appears that Google's servers saw the request as coming from IP address 66.220.144.148, which is indeed part of the facebookmail.com domain. The Google server verified the DKIM signature on the email, relatively to the public key found in the DNS as a TXT record for ...



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