Slashdot Mirror
SSLStrip Now In the Wild
An anonymous reader writes "Moxie Marlinspike, who last week presented his controversial SSL stripping attacks at Black Hat Federal, appears to have released his much-anticipated demonstration tool for performing MITM attacks against would-be SSL connections. This vulnerability has been met with everything from calls for more widespread EV certificate deployment to an even more fervent push for DNSSEC."
It's called a shotgun.
Bored at work? Play Game!
You could also try to read about it... The problem is not with SSL, it's with an attacker redirecting the traffic before it is in SSL, as your typical banking session usually start in plain HTTP. People then fail to understand the visual clues given by their browser. This attack is a nice technical MITM/social engineering mix, countermeasures are not really purely technical, if banks stopped to be cheap and did all their serving over HTTPS there would not be any HTTP traffic to modify in the first place...
Reading TFA, it seems to me that there IS something that the end user can do to protect themselves: Look for the https:/// in the address bar and DON'T LOOK THERE (favicon.ico area) FOR THE PADLOCK... the padlock should be down in the statusbar area where it always is.
Out of reflex, I always check that my URL starts with https:/// and I check the cert when I'm dealing with someplace new. Now, I'm just always going to check the cert... even if I'm connecting to a site I use all the time.
If Moxie really wanted to make things tougher, they could maybe add a cert to their tool. THAT would make it so you'd only notice if you read the cert and realized it wasn't what it was supposed to be.
THAT's scary.
The Digital Sorceress
This attack does not break SSL in any way. It simply tricks users into entering sensitive information into unencrypted context.
The solution is user education. We need to train users to look for the browser padlock icon. We need to add browser extensions that heuristically detect credit card numbers being entered into unencrypted sites and to warn the user. We need to train users to click "no" on security dialogs when they appear. We need to tell users that a padlock icon a website puts next to a form is unacceptable. We need to train users to be vigilant, because nasty people are trying to steal their information.
I'd like to see fewer people using self-signed certificates that train users to ignore SSL warnings. I'd like to see public service advertisements. I'd like to see basic computer safety classes in public schools. User education is the only hope we have against stupid users!
The fault lies partly with browsers too. Firefox, particularly, should never have toned-down the non-EV SSL user-interface --- sure, making EV special is fine, but allowing sites to spoof the SSL UI with a favicon is unacceptable. People have been saying this ever since Firefox 3 came out, but maybe now someone will pay attention to us.
Check to see if the URL to the site begins with http:/// before you login. If it does, and it's displaying a padlock icon (suggesting that it is 'secure'), then you're being attacked. Really, you should already be wary when a site asks you for login information over HTTP rather than HTTPS.
Also, as interesting as this attack is, it should be noted that it does require the attacker to have network access (so he can perform the MITM attack, usually through ARP spoofing). There are a number of ways to fight arp spoofing, but if you're on a small network, just set static arp tables on your machines and you've done pretty much all you can do. The attacker can still attempt to get access at your ISP and on the other end, at the web host, but handling that much traffic without being noticed would be difficult, so I doubt one would try it. (and I'm sure someone will now prove me wrong...:P)
We don't need an alternative to SSL. We need browsers to implement proper UI. The user MUST be made aware if clicking a button would transmit a password in cleartext. The user MUST be made aware exactly which domain they are connected to during an SSL session. On a large busy screen, a tiny bit of text in a corner is the wrong way to do this.
A slashdotter who didn't build his own computer is like a Jedi who didn't build his own lightsaber.