5 ms·

It's terrible, because Man-In-The-Middle attacks are trivial and automatable. namecheap.com sells PositiveSSL certs for $9/year -- that's pretty cheap and easy

It's terrible, because Man-In-The-Middle attacks are trivial and automatable. namecheap.com sells PositiveSSL certs for $9/year -- that's pretty cheap and easy.

itistoday2 12y ago
> It's terrible, because Man-In-The-Middle attacks are trivial and automatable. It's actually both terrible and the best security you can get. - Terrible because today's browsers participate in a pay-for-insecurity model, where any CA certificate can be used to compromise any website on the internet (except for the tiny number of hard-coded/"pinned" certs that some browsers ship for their company's websites). Certificate Transparency only makes the problem worse [1]. Browsers currently have no way to securely verify either self-signed OR CA-signed certificates. - It's the best security you can get because unlike certificates based on the aforementioned pay-for-insecurity "X.509 PKI" (public-key infrastructure), the security of a self-signed certificate depends on NO ONE except the issuer (i.e. _you_). Plus, they are 100% free. I like to refer to today's X.509 PKI as "the internet's oldest backdoor" (about two decades old now [2]), because browser vendors have been aware of this problem for quite some time now and haven so far chosen to either do nothing, or make the problem worse (like with Certificate Transparency [1]). Aaron Swartz wrote in 2011 that the solution to this problem is to use the blockchain [3]. I spoke with him about this at the time [4] and today am working on a project to bring that vision to life [5]. [1] http://www.ietf.org/mail-archive/web/trans/current/msg00233.html http://www.ietf.org/mail-archive/web/trans/current/msg00233.... [2] http://lists.randombit.net/pipermail/cryptography/2014-April/006482.html http://lists.randombit.net/pipermail/cryptography/2014-April... [3] http://www.aaronsw.com/weblog/squarezooko http://www.aaronsw.com/weblog/squarezooko [4] http://okturtles.com/img/Aaron_Swartz_Email.jpg http://okturtles.com/img/Aaron_Swartz_Email.jpg [5] https://github.com/okTurtles/dnschain https://github.com/okTurtles/dnschain
- zmanian 12y ago
  Ever mobile phone carrier makes themselves a root CA on devices they sell and routinely Man-In-The-Middle sites like Youtube.
- MyDogHasFleas 12y ago
  Aw come on, all you have to do is let your users choose an icon of their favorite animal or sport, save that as an account preference, and show it to them while they enter their password. We don't need better certificate verification!
  - hollerith 12y ago
    Yahoo did something very much like that about 5 or 6 years ago: inviting me to upload an image file, then telling me to make sure the image is present every time I log in. I upload an image file; the next time I found myself at Yahoo's login prompt, the image file was there; the time after that, it was absent. It has not re-appeared since. Just offering a data point: I don't know enough to have an opinion about the technique.
    - itistoday2 12y ago
      I think he was making a joke. Those pictures do nothing to prevent TLS MITM attacks.
      - gburt 12y ago
        I thought about this for a second, and what it does do is take an "offline" phishing attack and make it an "online" phishing attack that presumably has logs and can be throttled.
mark_l_watson 12y ago
Thanks. I needed some encouragement. I will buy two PositiveSSL certificates today.
- nmb 12y ago
  You might be able to use StartSSL's free one: https://www.startssl.com/ https://www.startssl.com/
  - kamaln7 12y ago
    Just keep in mind that Class 1 (free) certificates are for non-commercial sites only.
    - pyvek 12y ago
      Also, StartSSL's certs don't work on android (you get cert not trusted error) for some reason.
      - alec 12y ago
        Works for me - I have a StartSSL personal cert and an Android phone (Nexus 5 / KitKat), and all of Chrome, Chrome Beta, and Firefox load up the site without any sort of warning or other indication. I also dug out a Jelly Bean phone (Galaxy Nexus) to try with the stock Android Browser and didn't have any issues.
      - mike-cardwell 12y ago
        StartSSL has worked on Android since version 2.2, which was released 4 years ago.
      - dvanduzer 12y ago
        I haven't checked any recent Android trust stores, but this might be due to a lack of an intermediate certificate. The vast majority of modern browsers know how to find intermediate certificates online. Android's browser doesn't, for whatever reason. You have to bundle it on your web server.
rch 12y ago
I agree with your answer, but I don't recall ever seeing a post mortem write-up of such an attack. Are people who have seen them in the wild all bound my NDAs or something?
- stcredzero 12y ago
  I agree with your answer, but I don't recall ever seeing a post mortem write-up of such an attack. So, if you know how MITM operates, tell me: How would the server operator ever know?
  - rch 12y ago
    Reports of user data being compromised could lead to a consultant being hired to figure out where the security problem is, for instance. (I'm assuming the site requires a login or perhaps even takes CC information - the kind of stuff a user might notice a third-party using)
    - stcredzero 12y ago
      Reports of user data being compromised could lead to a consultant being hired... So right there, there's a good chance that it wouldn't get reported and there's less of a chance that management would understand the implications and hire the consultant.
  - cowbell 12y ago
    http://www.scmagazine.com/researchers-detect-ssl-mitm-attacks-method-implemented-by-facebook/article/346994/ http://www.scmagazine.com/researchers-detect-ssl-mitm-attack... About 0.2% for Facebook is MITM. And they are not using self signed certificates.
    - yaur 12y ago
      I'm going to go out on a limb here and say that the vast majority of that 0.2% are people sitting behind corporate proxies with a fake CA cert installed and pushed out to workstations via Group Policy. A hostile (and targeted) MITM could remove or alter the JavaScript that posts the fingerprint back to the server in which case it would be very difficult to detect. The problem with Self Signed Certs in a practical sense is that they enable a much broader range of attacks. Neither of them protect you from LEO and NSA. Neither of them protect you from the people that own and/or can run code on your PC. CA issued certs will protect you from the carder that is connected to the same public WiFi, but self signed certs wont.
cowbell 12y ago
Terrible compared to what? http? I don't understand why we get big scary warnings from browsers for self signed https, but never a peep out of them when submitting the same form over http.
- nav1 12y ago
  Because encountering a site with a self-signed certificate likely means that the connection is MITM'd. In any case, with a self-signed cert you can't who you're connecting to.
  - itistoday2 12y ago
    CA-signed certificates do not mean that you are not being MITM'd. They are actually worse in that they give everyone (including the browser) a false sense of security that you have to pay for. See detailed reply here: https://news.ycombinator.com/item?id=7826443 https://news.ycombinator.com/item?id=7826443
pbreit 12y ago
What could be achieved with a MitM attack on an information-only site?
- MichaelGG 12y ago
  Finding out what someone is interested in. Search queries or specific articles. Determining their browser information. If the site is particularly trusted (say, a news site), misleading users into trusting another party. If CNN ran an article about how adding some SSL cert to your trust store would make YouTube faster, a lot of people would do it. Or you could directly attack the user by providing false information.

It's terrible, because Man-In-The-Middle attacks are trivial and automatable. namecheap.com sells PositiveSSL certs for $9/year -- that's pretty cheap and easy.

itistoday2 12y ago

> It's terrible, because Man-In-The-Middle attacks are trivial and automatable. It's actually both terrible and the best security you can get. - Terrible because today's browsers participate in a pay-for-insecurity model, where any CA certificate can be used to compromise any website on the internet (except for the tiny number of hard-coded/"pinned" certs that some browsers ship for their company's websites). Certificate Transparency only makes the problem worse [1]. Browsers currently have no way to securely verify either self-signed OR CA-signed certificates. - It's the best security you can get because unlike certificates based on the aforementioned pay-for-insecurity "X.509 PKI" (public-key infrastructure), the security of a self-signed certificate depends on NO ONE except the issuer (i.e. _you_). Plus, they are 100% free. I like to refer to today's X.509 PKI as "the internet's oldest backdoor" (about two decades old now [2]), because browser vendors have been aware of this problem for quite some time now and haven so far chosen to either do nothing, or make the problem worse (like with Certificate Transparency [1]). Aaron Swartz wrote in 2011 that the solution to this problem is to use the blockchain [3]. I spoke with him about this at the time [4] and today am working on a project to bring that vision to life [5]. [1] http://www.ietf.org/mail-archive/web/trans/current/msg00233.html http://www.ietf.org/mail-archive/web/trans/current/msg00233.... [2] http://lists.randombit.net/pipermail/cryptography/2014-April/006482.html http://lists.randombit.net/pipermail/cryptography/2014-April... [3] http://www.aaronsw.com/weblog/squarezooko http://www.aaronsw.com/weblog/squarezooko [4] http://okturtles.com/img/Aaron_Swartz_Email.jpg http://okturtles.com/img/Aaron_Swartz_Email.jpg [5] https://github.com/okTurtles/dnschain https://github.com/okTurtles/dnschain

zmanian 12y ago
Ever mobile phone carrier makes themselves a root CA on devices they sell and routinely Man-In-The-Middle sites like Youtube.
MyDogHasFleas 12y ago
Aw come on, all you have to do is let your users choose an icon of their favorite animal or sport, save that as an account preference, and show it to them while they enter their password. We don't need better certificate verification!
- hollerith 12y ago
  Yahoo did something very much like that about 5 or 6 years ago: inviting me to upload an image file, then telling me to make sure the image is present every time I log in. I upload an image file; the next time I found myself at Yahoo's login prompt, the image file was there; the time after that, it was absent. It has not re-appeared since. Just offering a data point: I don't know enough to have an opinion about the technique.
  - itistoday2 12y ago
    I think he was making a joke. Those pictures do nothing to prevent TLS MITM attacks.
    - gburt 12y ago
      I thought about this for a second, and what it does do is take an "offline" phishing attack and make it an "online" phishing attack that presumably has logs and can be throttled.

mark_l_watson 12y ago

Thanks. I needed some encouragement. I will buy two PositiveSSL certificates today.

nmb 12y ago
You might be able to use StartSSL's free one: https://www.startssl.com/ https://www.startssl.com/
- kamaln7 12y ago
  Just keep in mind that Class 1 (free) certificates are for non-commercial sites only.
  - pyvek 12y ago
    Also, StartSSL's certs don't work on android (you get cert not trusted error) for some reason.
    - alec 12y ago
      Works for me - I have a StartSSL personal cert and an Android phone (Nexus 5 / KitKat), and all of Chrome, Chrome Beta, and Firefox load up the site without any sort of warning or other indication. I also dug out a Jelly Bean phone (Galaxy Nexus) to try with the stock Android Browser and didn't have any issues.
    - mike-cardwell 12y ago
      StartSSL has worked on Android since version 2.2, which was released 4 years ago.
    - dvanduzer 12y ago
      I haven't checked any recent Android trust stores, but this might be due to a lack of an intermediate certificate. The vast majority of modern browsers know how to find intermediate certificates online. Android's browser doesn't, for whatever reason. You have to bundle it on your web server.

rch 12y ago

I agree with your answer, but I don't recall ever seeing a post mortem write-up of such an attack. Are people who have seen them in the wild all bound my NDAs or something?

stcredzero 12y ago
I agree with your answer, but I don't recall ever seeing a post mortem write-up of such an attack. So, if you know how MITM operates, tell me: How would the server operator ever know?
- rch 12y ago
  Reports of user data being compromised could lead to a consultant being hired to figure out where the security problem is, for instance. (I'm assuming the site requires a login or perhaps even takes CC information - the kind of stuff a user might notice a third-party using)
  - stcredzero 12y ago
    Reports of user data being compromised could lead to a consultant being hired... So right there, there's a good chance that it wouldn't get reported and there's less of a chance that management would understand the implications and hire the consultant.
- cowbell 12y ago
  http://www.scmagazine.com/researchers-detect-ssl-mitm-attacks-method-implemented-by-facebook/article/346994/ http://www.scmagazine.com/researchers-detect-ssl-mitm-attack... About 0.2% for Facebook is MITM. And they are not using self signed certificates.
  - yaur 12y ago
    I'm going to go out on a limb here and say that the vast majority of that 0.2% are people sitting behind corporate proxies with a fake CA cert installed and pushed out to workstations via Group Policy. A hostile (and targeted) MITM could remove or alter the JavaScript that posts the fingerprint back to the server in which case it would be very difficult to detect. The problem with Self Signed Certs in a practical sense is that they enable a much broader range of attacks. Neither of them protect you from LEO and NSA. Neither of them protect you from the people that own and/or can run code on your PC. CA issued certs will protect you from the carder that is connected to the same public WiFi, but self signed certs wont.

cowbell 12y ago

Terrible compared to what? http? I don't understand why we get big scary warnings from browsers for self signed https, but never a peep out of them when submitting the same form over http.

nav1 12y ago
Because encountering a site with a self-signed certificate likely means that the connection is MITM'd. In any case, with a self-signed cert you can't who you're connecting to.
- itistoday2 12y ago
  CA-signed certificates do not mean that you are not being MITM'd. They are actually worse in that they give everyone (including the browser) a false sense of security that you have to pay for. See detailed reply here: https://news.ycombinator.com/item?id=7826443 https://news.ycombinator.com/item?id=7826443

pbreit 12y ago

What could be achieved with a MitM attack on an information-only site?

MichaelGG 12y ago
Finding out what someone is interested in. Search queries or specific articles. Determining their browser information. If the site is particularly trusted (say, a news site), misleading users into trusting another party. If CNN ran an article about how adding some SSL cert to your trust store would make YouTube faster, a lot of people would do it. Or you could directly attack the user by providing false information.