1

We're using lighttpd 1.5.0-2349 which unfortunately doesn't support the option to disable SSLv3. I think a potential workaround would be to only allow it to use some cipher which has already been disabled in most browsers, so that if SSLv3 is used, there is no cipher overlap between server and client.

Is this a good idea? Which cipher would be suitable for this purpose?

  • 5
    I would recomend you upgrading lighttpd. The version you are using have published vulnerabilities and exploits worse than Poodle. – ThoriumBR Oct 17 '14 at 15:34
  • I'll definitely try to upgrade it, but I'd like to apply a workaround in the meantime. BTW, which vulnerabilities are you talking about? I only found a couple and those only allowed DoS attacks. – JohnEye Oct 17 '14 at 16:14
  • I think DoS is a good enough reason to upgrade. – ThoriumBR Oct 17 '14 at 17:00
  • 1
    Of course it is, but it cannot leak any sensitive information, which is what I'm currently worried about. – JohnEye Oct 17 '14 at 17:24
5

There are secure non-POODLE-vulnerable ciphers which you can use with SSLv3 - POODLE only impacts variants with CBC. The RC4 ciphers, for example, are not vulnerable to POODLE. Now, RC4 is a tricky thing. It's considered breakable (but not really actively broken), but since it's the best workaround for things like BEAST and POODLE, it's heavily used and probably secure enough for some small window of time ahead.

Since you're going to upgrade lighttpd anyway, RC4 should be fine until you get that done :)

  • Please note that using RC4 cipher with SSL may open you up to a lawsuit, so tread carefully with this one. – user41341 Oct 17 '14 at 20:34
  • 1
    That article is from 2012. Since then they've robbed Newegg but lost to Intuit. I think it's clear that only people with really deep sue-worthy pockets need to worry about this patent troll, and even those people can leaven their fear with assurance that it's just a troll. – gowenfawr Oct 17 '14 at 21:06
  • Oh great! I remember the Newegg deal, but didn't see the Intuit one. – user41341 Oct 17 '14 at 22:42
  • I ended up completely disabling all configurations which used CBC, so when SSLv3 is used it only uses RC4. – JohnEye Oct 21 '14 at 12:47
3

I see where you are going with this, and it's good, out of the box thinking. Unfortunately it isn't likely to work in many cases - if a browser supports SSLv3 chances are it supports bad ciphers too.

My advice would be to put this system behind a web proxy where you can control the ciphers and protocols, and let the client connections terminate there. The client connects to the proxy using secure protocols and then the proxy connects to the insecure box.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.