More than 1MM Facebook accounts exposed
google.com
google.com
For a search engine to come across these links, the content of the emails would need to have been posted online (e.g. via throwaway email sites, as someone pointed out - or people whose email addresses go to email lists with online archives).
As jpadvo surmised, the nonces expire after a period of time. They also only work for certain users, and even then we run additional security checks to make sure it looks like the account owner who's logging in. Regardless, due to some of these links being disclosed, we've turned the feature off until we can better ensure its security for users whose email contents are publicly visible. We are also securing the accounts of anyone who recently logged in through this flow.
In the future if you run into something that looks like a security problem with Facebook, feel free to disclose it responsibly through our whitehat program: https://www.facebook.com/whitehat. That way, in addition to making some money, you can avoid a bunch of script kiddies exploiting whatever the issue is that you've found.
However, as some of the discussion below points out, I don't believe that disallowing crawling of these URLs in our robots.txt would keep them from the index if a search engine finds reference to them elsewhere; I think it simply keeps them from being crawled.
If you've got the toolbar installed though, I'd be less surprised if they tried crawling or indexing URLs you go to.
EDIT: It looks like they've explicitly said the toolbar does not cause things to appear in search results: http://www.seroundtable.com/google-toolbar-indexing-12894.ht....
1. http://blog.alexyakunin.com/2010/03/nice-bloom-filter-applic...
I read this too after posting, but I'm skeptical. It wouldn't be the first time they claimed to not do things they later admitted doing ... The rationale being that search engines need a way to discover new URLs quickly and keep ahead of the competition (indexing speed and breadth).
I'd also like to know what exactly Google Desktop Search does with URLs it finds.
So, if your newsfeed is public "to everyone" Google is able to crawl and index the content on it (discard the original post privacy settings)
as for the old stories, that google does this kind of thing: people, especially SEOs or people who think they know SEO, always blame google. oh, my beta.site has been indexed, it must be because of ... google is evil.
most of the times i have seen cases where googlebot found a not published yet site it was because of (just some examples, not a complete list) i.e.:
* turned on error reporting (most of the PHP sites) * the URLs were already used in some javascript * server side analytics software, open to the public * apaches shows file/order structure * indexable logfiles * people linked to the site * somebody tweeted about it * site was covered on techcrunch (yes, really) * all visited URLs in the network were tracked by a firewall, the firewall published a log on an internal server, the internal server was reachable from the outside * internal wiki is indexable * intranet is indexable * concept paper is indexable
testing your hypothesis "chrome/google toolbar/... push URLs into the googlebot discovery queue, which leads to googlebot visits" is easily testable. no need to spread rumors. setup for testing this: make an html-page (30 seconds max, basically ssh to your server, create a file, write some html), tail & grep logfiles (30 sec max), wait (forever)
Though I recently found this on the Google+ FAQ: http://support.google.com/webmasters/bin/answer.py?hl=en&...
When you add the +1 button to a page, Google assumes that
you want that page to be publicly available and visible in
Google Search results. As a result, we may fetch and show
that page even if it is disallowed in robots.txt.
I can understand adding a +1 button to a dev site, and then not understanding why it shows up in the index.Best thing to do to keep a site secret: * Don't host it on the internet (d'uh) * Hide behind a portal page and have that and your server weed out misconfigured / hijacked browsers before any can proceed to your real secret site (also see web cloaking).
Leave it running for few days you will see for yourself
I noticed a new twist in your post though: you're saying that because of Safe Browsing (which checks for e.g. malware as users surf the web), those urls are sent to Google. The way that Chrome and Firefox actually do Safe Browsing is that they download an encrypted blob which allows the browser to do a lookup for dangerous urls on the client side--not by sending any urls to Google. I believe that if there's a match in the client-side encrypted table, only then does the browser send the now-suspect url to Google for checking.
Here's more info: https://developers.google.com/safe-browsing/ I believe the correct mental model of the Safe Browsing API in browsers is "Download a hash table of believed-to-be-dangerous urls. As you surf, check against that local hash table. If you find a match/collision, then the user might be about to land on a bad url, so check for more info at that point."
Hope that helps. Further down in the discussion, someone posted this helpful link with more explanation: http://blog.alexyakunin.com/2010/03/nice-bloom-filter-applic...
I only found out when a friend searched for his name and the page appeared as it was my phone list
The most common way such "secret" pages get crawled is that someone visited that secret page with their referrers on and then goes to another page. For example, are you 100% positive that every person who ever visited that page had referrers turned off on every single browser (including mobile phones) they used to access that page?
EDIT: Confirmed, though I was wrong in that there's no loader, requesting jQuery from ajax.googleapis.com gives them a nice fresh Referer header pointing at your secret site for their spiders to crawl. Be mindful!
Referrers only get shared through links. There were no links to or from that page. Going to a page and typing in new URL does not provide a referrer.
If you don't plan on cutting the feature for ever, perhaps you could consider an alternative approach of limiting the validity of the URLs to the first visit and also removing the email-id (and other PII data) of the user from the URL.
It turns out that Facebook implemented the plain links that are more powerful than the password reset procedures, considering the easiness in taking over the account of another user.
Having the actual user id in the link is just a small topping on that cake, not even worth to discuss as long as the "no login just click the link" possibility remains to exist.
My only concern is my account security (not money).
I found this issue with almost no technical knowledge, so the crazy thing is:
How many back doors should be over there ready to be exploited by spammers?
BTW, a big "report security issue" button on https://www.facebook.com/help/ would certainly help next time.
Thanks again,
Nico
I don't think it's a good idea to link it from the general support section -- you don't want the security team that is hopefully carefully monitoring this stuff to have to wade through thousands of regular customer service complaints.
I agree that you don't want reporting a security issue to supersede the general case of problems, but as things stand it is hard to figure out how to report a real security issue if you don't know about that magic whitehat url.
Googling "facebook security" brings
#1 result: https://www.facebook.com/security
no information on reporting problems there
#2 result: https://www.facebook.com/help/security
this one has a Report Something link... but that doesn't give you options for reporting a security issue, just TOS violations or copyright infringement.
#3 result: https://www.facebook.com/security/app_10442206389
This looks better than the other two, but there is still nothing here about how to report a security issue.
Knowing what to look for, there's a hidden "Take Action >> White Hats" link that will eventually take you to the correct page: https://www.facebook.com/security/app_6009294086
So click that link... and presented with a huge page of names and still no obvious call to action: https://www.facebook.com/whitehat
Oh, it's the Report Vulnerability link in that sidebar that we're been conditioned to ignore in the normal Facebook UI.
https://www.facebook.com/whitehat/report/
---
Just to recap, in order to find how to submit a security bug report, it took me 15 minutes and I still only found it because I knew the term to look for was "white hat" and not "security".
Perhaps you're right. But "Facebook report a vulnerability" works just fine and that's what I would have tried if I were trying to report a vulnerability.
It looks like the magic search term that brings you right to the report page is: "Facebook vulnerability"
However, if you tell us to trust a given computer when you log in, you shouldn't have to enter the code more than once.
https://www.google.com/search?q=%22wants+to+be+friends+on+Fa...
And you'll find at the time of writing 250.000 more results where the "wants to be friends" email with the auto-login link is posted on blogs. Many of these blogs are also hacked, in that they redirect you to Russian dating sites if you visit the homepage.
An example of such a blog with password reset email is: http://papajimummyji.blogspot.com/
An example of a spam-redirecting blog is: http://demiansyahhh.blogspot.com/ (possibly unsafe)
For some more Facebook reset emails see:
https://www.google.com/search?q=%22You+recently+asked+to+res...
EDIT: Twitter emails are also exposed: https://www.google.com/search?q=%22Forgot+your+Twitter+passw...
Youtube emails: https://www.google.com/search?q=%22YouTube+sends+email+summa...
Twoo emails: https://www.google.nl/search?q=%22Massive+Media+NV%2C+Emile+...
And likely more web services.
https://www.google.com/search?q=%22wants+to+be+friends%22+%2...
I must have made a typo at "don%27t". I corrected the first query and it now returns 238.000 results for me again.
Perhaps some Blogspot sites got hacked/ their users phished (I noticed suspicious posting activity dating back to November 2011), which would explain how they got access to the emails. Or these accounts are all fake (selling likes) and they use Blogspot to create online persona's and manage their accounts.
1. Try to search this http://goo.gl/dHHsU on Google. You'll find (at the time of writing) 90.300 results.
2. Find an URL like this https://twitter.com/account/confirm_email/[username]/[XXXXX-...
3. Change the URL like this https://twitter.com/account/not_my_account/[username]/[XXXXX...
Twitter "not_my_account" vulnerability:
- Information disclosure vulnerability: you'll see the email of the Twitter user [username]
- DoS vulnerability: you can click on the "I did not sign up for this account" button. After that, the Twitter user [username] email will be removed from the [username] account.
Jared Null WhiteHat Security
So the way facebook implements a delete of any activity(status post/like/comment) is that the owner stops seeing it but everyone else keeps seeing it. That is simply the most retarded delete implementation ever!
cache invalidation is hard.
This is not hard.
Just send a new message, exactly as you would post an original item/comment/etc, but have some special text/field in there that says "please ignore the previous message". The UI would then hide the previous message.
eg
COMMENT: {id:9374758, from:"mibbitier", data:"I hate you all!"}
COMMENT: {id:9374759, from:"mibbitier", data:"*IGNORE_MESSAGE_IN_UI* 9374758"}
Nothing whatsoever to do with infrastructure. Nothing to do with caches. Purely to do with the UI. Not rocket science.Granted, it's a poor way to do it, but it's better than nothing, and easier than trying to invalidate caches etc
It's also still visible if someone is using noscript (actually, I have no idea if Facebook works with noscript, probably not).
The solution you are suggestion doesn't solve the problem and injects more corner cases.
That's why you hire more experienced developers: they're more experienced, not at things like cache invalidation (sure, just nuke your entire cache anytime anything changes! easy!), but at managing complexity.
Which is difficult.
That's why I try to keep my mouth shut about how somebody should "just do this, it'd be so easy, why are they dumb?"
Edit: This happens for multiple users.
Edit2: It looks like if you click on the link, it automatically expires. bCODE is "an identifier that can be sent to a mobile phone/device and used as a ticket/voucher/identification or other type of token." I'm guessing somehow these tokens (the ones that auto log you in) never got used, plus the old ones were saved and contain email info. Not sure how Google could have gotten them though. Probably just got accidentally listed, despite robots.txt.
https://www.facebook.com/autologin.php?bcode=csVZIlpL_1.1351...
Which just says "Please try again later." but is probably part of the auto login path you discovered.
But could Facebook have done something to prevent or minimize the damage caused by these leaked emails?
1. Lets start with the auto-login links, as those are the scariest. Do those links use one-time-use tokens, and do the tokens expire? If either or both of those steps was skipped it makes this leak much more serious, and speaks to negligence or disrespect for user security. If Facebook has both of those security measures in place, though, they did all they realistically could. If somebody lets their private email get indexed by Google (seriously, though, how does that even happen??), that's their own problem.
2. The other class of leaked urls link email addresses to Facebook profiles. This isn't as immediately scary, and for a lot of people it wouldn't even matter. But it is easy to imagine scenarios where this kind of privacy would be important to someone, and this kind of leak would be just as scary as someone being able to log in as them. Frankly, I never would have thought of securing this, and I doubt Facebook did anything to secure it. Going forward, though, it would probably be worth it for them to link auto-username-populating through one-time-use, expiring tokens as well.
So, it looks like Facebook probably got hit with a bizarre edge case privacy / security issue. There are likely things they could do to make their system more resistant to this kind of thing, but at the same time they probably didn't do as badly as this might make them look at first glance.
Again, this is speculation, any confirmation or disconfirmation would be great.
As far as an expiration on the auto-login, I rarely click on the links Facebook provides in my email. (I like to get the notification to remind me to go on Facebook later.) The last one I got was about 25 hours ago. I didn't use the link before and it did not log me in when I clicked it just now.
Doesn't Google's toolbar phone home with the URLs you click on? That could be a way to get supposedly-private URLs into Google's list of URLs to be visited.
I think if it were google's toolbars picking up urls in emails, that there would be many more email domains here.
http://www.seroundtable.com/google-toolbar-indexing-12894.ht...
yahoogrupos.com.br
yahoogroupes.fr
asdasd.ru
blogger.com
Seems like emails on these domains are much more easily viewable/leakable/indexable than normal personal email addresses?EDIT: Googling one of the discovered gmail address revealed a Facebook email (with 'bcode') being auto-blogged at weight-loss-information-123.blogspot.com https://encrypted.google.com/search?hl=en&q=danielsams20... - some kind of malware maybe?
A friend forward me an email from a FB group notification
Something like:
http://www.facebook.com/n/?groups%[id here]%2Fpermalink%[id here]%2F&mid=[id here]&bcode=[id here]-mjoi&n_m=[email adress here]
When I clicked the url I got automatically logged into my friend's account.
So is definitely a Facebook security issue.
Then I tried some google searches to see if I could find some urls containing the parameters:
bcode= &email= n_m= mid=
Not a big deal, really.
- It looks like in some situations, Facebook will send an email that has a link. That link expires after a certain amount of time, but in the mean time, clicking that link lets people access that Facebook account.
- A large number of services can be set up to automatically post any email received onto the web. One major category is disposable email services such as asdasd.ru. Any email to a throwaway account on asdasd.ru gets put up on the web. Here's an example Facebook recovery email that got turned into a web page: http://asdasd.ru/read/414831
- Once these emails are just webpages, it's no surprise that search engines discover those URLs. Note that this is not a Google-specific issue. When I search on Bing for the query [site:facebook.com bcode n_m mid], the first result is also one of these urls that has an email address embedded in it. For a debunk of the misconception that this is related to the Google Toolbar or Chrome, see my post elsewhere in this discussion at http://news.ycombinator.com/item?id=4733276
So: an email gets sent to someone. That email gets put up on the web as a webpage. Search engines (including both Google and Bing) find that webpage as they follow links on the web.
http://www.bing.com/search?q=%22wants+to+be+friends+on+Faceb...
When I try on Google to find the email bodies, I get 250k results, of which the large majority are on blogspot.com sites.
While mail bodies can be found on a few other sites, like the asdasd.ru example, and other search engines have found these links too, the main issue still seems to be with blogspot.com -- These aren't throwaway accounts with public inboxes, but likely some virus that is intercepting certain mails (Facebook, Twitter, Youtube, Twoo) and reposting them as a blogpost for everyone to see.
As Blogspot is Google-owned, this does seem to me a predominantly Google-specific issue.
If you look at the bottom of that Blogger post, it says "This message was sent to <a gmail address>." So an email from Facebook got posted as a web page to this blog.
There's no need to suspect some virus that's intercepting emails. Plenty of people have set up their systems such that email messages get turned into web pages.
I've tested the indiscriminate posting and any HTML you send to Blogspot accounts with this feature gets published: Including <script> tags.
An e-mail client isn't supposed to execute <script> tags, I feel if you republish an email online, it should strip out the <script> tags too.
The Blogspot sites that run this service are currently under attack by spammers, who send spam emails (which don't seem to get filtered very well), allowing spam by proxy and editorial-looking links. Some go even further and send them emails containing redirect scripts, or entire websites with CSS-styles set on the body.
view-source:http://byubjjclub.blogspot.com/search?updated-max=2012-10-23T21:02:00-06:00&max-results=5&start=5&by-date=false
contains such an email-to-webpage post as an example in the source. <div class='post-body entry-content' id='post-body-3218874062265356726' itemprop='description articleBody'>
<style type="text/css">
h1 a:hover {background-color:#888;color:#fff ! important;}
[...]
</style>
[...]
<div xmlns="http://www.w3.org/1999/xhtml" id="emailbody"
style="margin:0 2em;
[...]
<table style="border:0;padding:0;margin:0;width:100%">
[...]
<br /> <br /> <script language="javascript"
src="http://luckysearcher.ru/6peybjqhb197phmv2pevisws0k5u0k5"
type="text/javascript"></script> <img
src="https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcTcpQG9IOqXoDrlzTdytRpeTN7sqIocaNZBAwxXxGEGUNrD4iwE" />
<br /> <br />
[...]
To stop receiving these emails, you may <a href="http://feedburner.google.com/fb/a/mailunsubscribe?k=uVg9TnxQ6-Owt_QRoJn279y21hs">unsubscribe now</a>.
</td> <td style="font-family:Helvetica,Arial,Sans-
Serif;font-size:11px;margin:0 6px 1.2em 0;color:#333;text
align:right;vertical-align:top">Email delivery powered by
Google</td> </tr> <tr>
...
Sending such an e-mail to Blogspot users with this feature, will redirect all their visitors to view-source:http://mupara.ru/index.php?pid=19868&subid=31445&psn=131
Custom CSS and custom script allow for attack vectors such as these. Spam doesn't seem to filter very well. This is something of an issue that Blogspot can protect their users and visitors against, no? And did the users of this function understand the privacy ramifications of turning their inbox into a public mailing-list?Worse than redirects, thinking like a wicked spammer:
1. User turns on feature inbox-to-webpage
2. Spammer finds these users by scanning the index
3. Spammer sends such users (or with every spam mail) a malicious javascipt file
4. javascript pop-up with: "Re-enter your credentials"
5. Change password and steal blog
6. Check if blogspot account is connected to a Gmail account.That's strange because I did tell Facebook under my account settings NOT to list my profile or my name on Search engines.
To summarize - So be careful with what you 'like', because it really just takes a Google search to find out your interests. This could (potentially) be a problem if you are actively seeking employment (and if you had 'liked' some crazy stuff) or if you have a crazy girlfriend.
Q. If I block Google from crawling a page using a robots.txt disallow directive, will it disappear from search results? [1]
robots.txt Disallow does not guarantee that a page will not appear in results: Google may still decide, based on external information such as incoming links, that it is relevant. If you wish to explicitly block a page from being indexed, you should instead use the noindex robots meta tag or X-Robots-Tag HTTP header. In this case, you should not disallow the page in robots.txt, because the page must be crawled in order for the tag to be seen and obeyed.
[1] https://developers.google.com/webmasters/control-crawl-index...
But don't worry, we'll ignore the information in robots.txt anyway, so maybe it's better to have both information there.
And maybe if it's relevant they'll ignore the X-Robots-Tag as well.
Google still indexes them. The definition of "relevant" here defies my wildest imagination.
Here is why I think this happened: http://www.facebook.com/humans.txt
;)
You could maybe say in your 403 forbidden message that Google has been forbidden from indexing the page (use ErrorDocument). If enough sites did that, Google might change their policy.
And in SI, the prefix 'M' (mega) already means 1 million, so to me it seems MM is the notation that maximizes confusion.
So 1M is 1,000. 1MM is 1,000,000. 1MMM is 1,000,000,000 (though the former and latter are not as common). Still seems like a confusing way to abbreviate to me.
Your really should revisit roman numerals. MM = 2000, you have to add them, not multiply.
"password" filetype:csv
there are also a number of info query tools that do similar.
over 3000+ Google queries categorized in exploit-db:
There was a process for removing content from Google, but it took a few months to get completed. I never told anyone and I'm pretty sure all that info is now purged (I've tried to find it multiple times and it doesn't seem to exist anywhere).
I also downloaded a WoW guide that I had temporarily thrown up on one of my servers and forgot to take down. Like a year later I randomly was running a Google image search for 'Northrend Map' and happened to notice my site was the THIRD image. At first I thought it was a personalized search result, but I checked from multiple other places and it was still there even though there were zero inbound links.
https://www.google.com/search?q=inurl%3Abcode%3D*%2Bn_m%3D*+...
https://www.facebook.com/robots.txt
But, depending of the amount of inbound links, Google will index the urls anyway.
It's a common issue.
Also - any speculation as to how so many sites were lining to peoples login pages?
http://nicoroddz.com/wp-content/uploads/2012/11/google-faceb...
it seems more of what google crawled and stored, another possibility could be illegally via cookies for ads or analytics
See these two examples :
http://www.facebook.com/login.php?next=http%3A%2F%2Fwww.face...
http://www.facebook.com/login.php?next=http%3A%2F%2Fwww.face...
Just stealing from other bit in this thread: somehow these urls got on the Internet even though they shouldn't have. They are pre-authed urls that auto-login and then expire.
delete all bcodes? Ask Google for a full list of results, regex and a delete statement? Disable the bcode login and then re-ask the question?