[tor-talk] 12.7 percent of the domains I visit are intercepted by CloudFlare

Rob van der Hoeven robvanderhoeven at ziggo.nl
Sat Apr 23 19:54:24 UTC 2016


On Sat, 2016-04-23 at 14:03 -0500, Joe Btfsplk wrote:
> On 4/23/2016 8:15 AM, Rob van der Hoeven wrote:
> > Hi,
> >
> > Today I got an idea of how to measure "The CloudFlare problem". It turns
> > out that every time you visit a website that's behind CloudFlare a
> > cookie is set with the name __cfduid
> >
> > If you use Firefox these cookies end up in a SQLite database which can
> > be queried with the SQLite Manager add-on. My total number of cookies is
> > 2523 (I disable third-party cookies by default). CloudFlare cookies:
> > 321. So 321/2523 *100 = 12.7% of the domains I have visited are
> > monitored by CloudFlare. Quite shocking I think.
> >
> > Rob.
> > https://hoevenstein.nl
> >   
> Are you saying using TBB, cloudflare sets cookies withOUT either
> checking "accept cookies from sites;"
> or entering an exception for their domain in TBB's cookie exceptions;
> or when in Options > Privacy - "Accept 3rd party cookies" = Never?
> 

I am not using TBB. Sorry I was not clear about this. I use the normal
Firefox, enhanced with NoScript, AddBlockPlus etc. I changed the privacy
settings so that "Accept cookies from sites" is allowed, but "Accept
third-party cookies" is set to "Never"

Now the interesting (nasty) properties of CloudFlare cookies are:

1) They are not coming from the CloudFlare domain, but from the domain
you are visiting. If you surf to abcdef.com and that site uses
CloudFlare then the CloudFlare cookie is set for the abcdef.com domain.
CloudFlare clearly is a third-party, but their cookies can not be
disabled by refusing third-party cookies. 

2) Many of *my* CloudFlare cookies have an expiration date of 23 dec
2019. These are clearly ment to be tracking cookies. 

Rob.
https://hoevenstein.nl




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