oss-sec mailing list archives
Re: attacking hsts through ntp
From: Kurt Seifried <kseifried () redhat com>
Date: Thu, 16 Oct 2014 14:34:25 -0600
On 16/10/14 01:45 PM, Hanno Böck wrote:
Am Thu, 16 Oct 2014 09:56:06 -0600 schrieb Kurt Seifried <kseifried () redhat com>:The obvious solution being to whitelist your site (in the chrome/firefox source code)if you truly care:No. While this is neat (and I already did this for my most important domains) this won't help. The reason: HSTS preloaded sites are handled exactly the same way as normal HSTS sites - they can expire. Chrome sets a maximum timeout for HSTS of 1000 days for preloaded sites. That was elaborated in the talk today. He demonstrated the attack on google mail which is in this whitelist. Set clock 3 years into the future and youre done.
I did not know that. One concern I have is also HSTS has no tools to manage them in browsers, at least when I last checked, has that changed? There is some room for DoS due to this on the client side.
It could be argued that it is wrong to expire preloaded HSTS sites. But the very same attack applies to HPKP which basically has to expire, because you don't want to use keys forever.
If people say "I use HSTS, so much so that I want you to whitelist it IN the source code forever" I'm pretty sure they never want it to expire (at least that was my thought when I got my domains whitelisted). -- Kurt Seifried -- Red Hat -- Product Security -- Cloud PGP A90B F995 7350 148F 66BF 7554 160D 4553 5E26 7993
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Current thread:
- attacking hsts through ntp Hanno Böck (Oct 16)
- Re: attacking hsts through ntp Kurt Seifried (Oct 16)
- Re: attacking hsts through ntp Lukas Reschke (Oct 16)
- Re: attacking hsts through ntp Hanno Böck (Oct 16)
- Re: attacking hsts through ntp Kurt Seifried (Oct 16)
- Re: attacking hsts through ntp Hanno Böck (Oct 16)
- Re: attacking hsts through ntp Kurt Seifried (Oct 16)
- Re: attacking hsts through ntp Michal Zalewski (Oct 16)
- Re: attacking hsts through ntp Hanno Böck (Oct 16)
- Re: attacking hsts through ntp Adam Langley (Oct 16)
- Re: attacking hsts through ntp Kurt Seifried (Oct 16)
- Re: attacking hsts through ntp Kurt Seifried (Oct 16)
- Re: attacking hsts through ntp Hanno Böck (Oct 17)
- Re: attacking hsts through ntp Yves-Alexis Perez (Oct 17)
- Re: attacking hsts through ntp Stephen Röttger (Oct 17)