SSL for logged in users? [closed] - security

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For a website which offers free content and paid content (when the user is logged in), should it operate over SSL (i.e. https)?
More to the point- for pages other than the registration page, there is sometimes content like facebook like, third-party banners, etc. When I view those pages in various browsers, I get warnings that the page is not completely secure, since some of the content is unprotected.
Is there a standard for this, and reasons why?
I've noticed, for example, that gmail keeps it over https while facebook opts for http...

Regarding the first question: you should consider using HTTPS for your website for user authentication and their usage once authenticated, because most authentication methods (typically cookie-based, session-ID in the URL or HTTP Basic) would transmit the authentication token (e.g. the cookie) in clear otherwise. As such, an eavesdropper could impersonate the authenticated user by re-using the session-ID/cookie for themselves. This sort of attack has been around for a long time, but tools like Firesheep, in conjunction with the use of unprotected (possibly public) WiFi networks makes this quite practical unfortunately.
Regarding the second question: you get those warnings for mixed-content, i.e. pages served over HTTPS that embed content from HTTP sites. If you're using secure cookies, your authentication token (in the cookie) shouldn't leak to the non-protected content embedded on the page... However, it's impossible for the use to know that. Teaching users to ignore warnings is generally bad practice.
If it's your content, turn on HTTPS. If it's someone else's and they don't have HTTPS access, it's a bit trickier. One solution may be to relay their content through your website (but you would need to rewrite their links, etc.).
As always, it's a matter of risk assessment. You can actually use Facebook over HTTPS (by typing https:// explicitly). Since posting on Facebook can have you sent to prison, you wouldn't want anyone impersonating you.
Some sites don't enable HTTPS because it's thought to be expensive, which isn't necessarily true (Compatibility of XP for Server Name Indication and shared hosting is also an issue, as detailed in this article too).

SSL is computationally expensive; serving pages over SSL will make your site a little slower (especially with lots of traffic). (you can replace the computational expense with financial expense by buying separate SSL hardware)
Gmail serves everything under SSL because they believe that all of your email content is confidential.
Basically, they think that email needs to be more secure than Facebook.

Related

is it safe to fetch an image on plain http on a bank's homebanking website?

I ask here instead of https://security.stackexchange.com/ because I dont think this question is on a professional level.
I just saw something weird on my bank's website, they are fetching an image from another domain, using http instead of https , on firefox it raises a security "mixed content" alert, on chrome it just shows up an alert on the security tab.
This is the site: https://www.bancoprovincia.com.ar/Principal/BipPersonal
The unsafe content (an image) happens to be on the page just before the user logs in to his home banking, I was worried that some attacker could intercept the content and replace it with something that could be a security risk.
Any chance this is a security risk for the bank and it's clients?.
It's not a direct vulnerability, but still bad practice.
Some risks that come to mind:
An attacker having access to users' connections (man in the middle) could replace the image with a malicious one, exploiting potentially zero-day (as yet unknown) flaws in browser or operating system image processor libraries. This could lead to remote code execution on the client.
Replacing the image could also be used to facilitate phishing. The malicious image could tell the user to call a phone number because of some kind of a problem, etc.
It is an information leak. An attacker may receive information about users browsing to the bank website, also if the image is in a header included on all pages, they may receive information about what the user does. This is inherently the case for every external site that has its images linked even over https, but over http this also applies to any MitM attacker.
It is a potential availability problem. If the image on the external site times out (waits too long to download), the page will not load for some time in some browsers and an attacker could exploit that. However, this I think is not affected by the image being served on plain http, it would affect an externally linked https image as well I think.
It's also a very bad practice, because instead of strengthening good security practices in users like always checking browser indications of a secure website, it is telling them that it's ok if there are warnings. It is not.

phantomjs --web-security=no

In the documentation for phantomjs, there is an option to turn off web security and allow XHR (cross domain requests).
Does this present a security risk to a user if you are filling forms with credentials such as usernames and passwords and then downloading screenshots with casper/phantom?
Maybe.
Allowing cross domain XHR opens up a few attacks. E.g. see https://stackoverflow.com/a/7615287/841830. See also Is CORS a secure way to do cross-domain AJAX requests?
But this tends not to come up with the normal use cases for Phantom: whether you are testing your own web site, or screen-scraping, you tend to go to pre-decided URLs and links, and are not sending secret information, and are not going to be tricked by a new and suspicious link. You are unlikely to be logged into your bank, or Facebook, while testing your site or scraping google search results. (BUT, if you are scraping google pages that force you to sign into Google first, be a bit more careful - perhaps set up a dedicated gmail account just for your scraping.)
So, in summary, the attacks are a bit more obscure and unlikely, compared to a normal desktop browsing session, but they are still there, so only use --web-security=no when your script otherwise will not work.

Is "Post"ed information from non-SSL to an SSL secure?

I am looking into Authorize.net's new "Direct Post Method" for handling credit card transactions. Previously, my company has been using Auth.net's AIM to process credit cards without leaving our website. This method requires that we have an SSL.
However, this new DPM that Auth.net has says that the client still pays on our website but we don't need an SSL for security. This seems a bit odd to me but that's what Auth.net says. You can see the charts here: http://developer.authorize.net/api/compare/.
So, my question is this; if I have a page hosted without an ssl (http://etc...) that posts to an SSL (https:///etc...) is the POSTed information secure?
Thanks for any help.
Technically, the information may be secure in transit (after hitting the submit button). But the person filling out the form can't possibly know that it will be secure (so why should they trust your site?). After all, if the URL bar doesn't indicate that it is an HTTPS page, how are they supposed to know that it will POST to an HTTPS site?
I wrote about this once before. Although I was accused of being overly paranoid, I still maintain that I wouldn't trust a site with my credit card details if the page that I'm submitting from (and to, of course) are both SSL.
Look: The whole point of SSL is to prevent man-in-the-middle attacks (that's all it does). If your form isn't protected, then an attacker could modify the form to submit to wherever they want.
Man-in-the-middle attacks allow an attacker to modify or monitor information while in transit across the internet. With the prevalence of insecure wireless networks, BGP poisoning, attacks on DNS and new vulnerabilities being discovered every day, it's also becoming increasingly easy to perform a man-in-the-middle attack.

How important is it to use SSL on every page of your website? [closed]

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Recently I installed a certificate on the website I'm working on. I've made as much of the site as possible work with HTTP, but after you log in, it has to remain in HTTPS to prevent session hi-jacking, doesn't it?
Unfortunately, this causes some problems with Google Maps; I get warnings in IE saying "this page contains insecure content". I don't think we can afford Google Maps Premier right now to get their secure service.
It's sort of an auction site so it's fairly important that people don't get charged for things they didn't purchase because some hacker got into their account. All payments are done through PayPal though, so I'm not saving any sort of credit card info, but I am keeping personal contact information. Fraudulent charges could be reversed fairly easily if it ever came to that.
What do you guys suggest I do? Should I take the bulk of the site off HTTPS and just secure certain pages like where ever you enter your password, and that's it? That's what our competition seems to do.
Here's the issue, and why banks are still horribly vulnerable: their landing page is HTTP, so it can be man-in-the-middled. Then they have a link to the login, and the login page is HTTPS.
So if you go directly to the login page, you can't be Man-in-the-Middled. But if you go to the homepage/landing page, since I control that, I'm going to rewrite the login page link to be HTTP. Then I'll do a SSL handshake with the login page, and send you (the user) the insecure version. So now you're (the user) doing all your sensitive transactions - and the server thinks it's HTTPS - and I'm in the middle doing shenanigans.
This is a very hard problem to solve completely because it goes all the way down to the DNS level on the server-side, and all the way down to default actions in browsers on the client-side.
As a content provider, you could try putting in javascript to check that the secure areas of your site are being accessed securely (and hope that I, as a cracker, don't remove that js before forwarding it). You can also include your happy "Please make sure this site is accessed via https" banners.
As a user, NoScript has an option to make sure sites are in HTTPS.
There's a new technology (I believe it's a marker on DNS entries maybe?) not supported by all clients/servers that lets a server opt in and say it is only accessible via HTTPS and to die a fiery death if it's being MITM-ed. I can't for the life of me recall or able to find it on google though...
I would take the bulk of the site off HTTPS with some exceptions of course:
Any checkout or account editing screens.
Any screens that would display "sensitive" information.
To deal with the session hijacking issue, I would add another layer of authentication where you prompt them for their username and password again at checkout or whenever they try to view/update account information - basicly whenever you make a transition from http to https.
Yes, I would just use SSL to secure important elements such as input fields, passwords, etc. I believe that's what most sites do, including online banking sites.

Is it secure to submit from a HTTP form to HTTPS?

Is it acceptable to submit from an http form through https? It seems like it should be secure, but it allows for a man in the middle attack (here is a good discussion). There are sites like mint.com that allow you to sign-in from an http page but does an https post. In my site, the request is to have an http landing page but be able to login securely. Is it not worth the possible security risk and should I just make all users go to a secure page to login (or make the landing page secure)?
Posting a form from an http page to an https page does encrypt the data in the form when it is transmitted in the most simple terms. If there is a man-in-the-middle attack, the browser will warn you.
However, if the original http form was subjected to man-in-the-middle and the https post-back address was modified by the attacker, then you will get no warning. The data will still actually be encrypted, but the man-in-the-middle attacker would be able to decrypt (since he sent you the key in the first place) and read the data.
Also, if the form is sending things back through other means (scripted connections) there may be a possibility of unencrypted data being sent over the wire before the form is posted (although any good website would never do this with any kind of sensitive data).
Is there any reason not to use HTTPS for the entire transaction? If you can't find a very good one, use it!
It's arguably simpler than switching protocols.
The MITM risk is real.
Following your link, the user "Helios" makes an excellent point that using 100% HTTPS is far less confusing to the user.
This kind of thing is popping up all over the net, especially in sites for which login is optional. However, it's inherently unsafe, for quite subtle reasons, and gives the user a false sense of security. I think there was an article about this recently on codinghorror.com.
The danger is that while you sent your page with a post target of "https://xxx", the page in which that reference occurs is not secure, so it can be modified in transit by an attacker to point to any URL the attacker wishes. So if I visit your site, I must view the source to verify my credentials are being posted to a secure address, and that verification has relevance only for that particular submit. If I return tomorrow, I must view source again, since that particular delivery of the page may have been attacked and the post target subverted - if I don't verify every single time, by the time I know the post target was subverted, it's too late - I've already sent my credentials to the attacker's URL.
You should only provide a link to the login page; and the login page and everything thereafter should be HTTPS for as long as you are logged in. And, really, there is no reason not to; the burden of SSL is on the initial negotiation; the subsequent connections will use SSL session caching and the symmetric crypto used for the link data is actually extremely low overhead.
IE Blog explains: Critical Mistake #1: Non-HTTPS Login pages (even if submitting to a HTTPS page)
How does the user know that the form is being submitted via HTTPS? Most browsers have no such UI cue.
How could the user know that it was going to the right HTTPS page? If the login form was delivered via HTTP, there's no guarantee it hasn't been changed between the server and the client.
Jay and Kiwi are right about the MITM attack. However, its important to note that the attacker doesn't have to break the form and give some error message; the attacker can instead insert JavaScript to send the form data twice, once to him and once to you.
But, honestly, you have to ask, what's the chance of an attacker intercepting your login page and modifying it in flight? How's it compare to the risk of (a) doing a MITM attack strait on the SSL session, and hoping the user presses "OK" to continue; (b) doing the MITM on your initial redirect to SSL (e.g., from http://example.com to https://example.com) and redirecting to https://doma1n.com instead, which is under the attacker's control; (c) You having a XSS, XSRF, or SQL injection flaw somewhere on your site.
Yes, I'd suggest running the login form under SSL, there isn't any reason not to. But I wouldn't worry much if it weren't, there are probably much lower hanging fruit.
Update
The above answer is from 2008. Since then, a lot of additional threats have become apparent. E.g., access sites from random untrusted networks such as WiFi hotspots (where anyone nearby may be able to pull off that attack). Now I'd say yes, you definitely should encrypt your login page, and further your entire site. Further, there are now solutions to the initial redirect problem (HTTP Strict Transport Security). The Open Web Application Security Project makes several best practices guides available.
This post is the key one. Yes, if the user's data is sent to you, it will have arrived somewhere securely. But there is no reason to believe that somewhere will be your site. The attacker isn't just going to get to listen to the data moving in each direction at this point. He'll be the other end of the user's session. The your site is just going to think the user never bothered to submit the form.
For me (as an end-user), the value of an HTTPS session is not only that the data is encrypted, but that I have verification that the page I'm typing my super-secrets into has come from the place I want it to.
Having the form in a non-HTTPS session defeats that assurance.
(I know - this is just another way of saying that the form is subject to an MITM attack).
No, it's not secure to go from HTTP to HTTPS. The originating and resulting points of the request must be HTTPS for the secure channel to be established and utilized.
Everyone suggesting that you provide only a link to the login page seems to be forgetting that the link could easily be changed using a MITM attack.
One of the biggest things missed out in all of the above is that there is a general trend to place a login on a home page (Huge trend in User Experience Trends).
The big problem here is that Google does not like to search secure pages with good reason, so all those Devs who are wondering why not make it all secure, well if you want your page invisible to Google, secure it all. Else, the second best option to post from http to https is the lesser of two evils at this point?
I think the main consideration of this question has to do with the URL that users know and the protocol scheme (http:)that browsers substitute by default.
In that case, the normal behavior of a site that wants to ensure an encrypted channel is to have the http://home-page redirect to https://home-page. There is still a spoofing / MitM opportunity, but if it is by DNS poisoning, the risk is no higher than if one starts out with the https: URL. If a different domain name comes back, you need to worry then.
This is probably safe enough. After all, if you are subject to a targetted MitM, you might as well start worrying about keyboard loggers, your local HOSTS file, and all sorts of other ways of finding out about your secure transactions involving your system already being owned.

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