CGI-Browser-CGI qux.com foo.org geht.net bar.com . p.1/ ?? - - PowerPoint PPT Presentation

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Jun 11, 2023 178 likes •461 views

CGI-Browser-CGI qux.com foo.org geht.net bar.com . p.1/ ?? CGI-Browser-CGI qux.com foo.org /cgibin/img.pl /cgibin/img.pl geht.net bar.com /cgibin/img.pl /cgibin/img.pl . p.1/ ?? CGI-Browser-CGI qux.com foo.org

SLIDE 1

CGI-Browser-CGI

qux.com geht.net foo.org bar.com

. – p.1/??

SLIDE 2

CGI-Browser-CGI

/cgi−bin/img.pl

geht.net foo.org bar.com qux.com

/cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl

. – p.1/??

SLIDE 3

CGI-Browser-CGI

img.gif

geht.net foo.org bar.com qux.com

/cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl img.gif img.gif img.gif

. – p.1/??

SLIDE 4

CGI-Browser-CGI

http://harmless.org/index.html

geht.net foo.org bar.com qux.com

/cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl img.gif img.gif img.gif img.gif

. – p.1/??

SLIDE 5

CGI-Browser-CGI

geht.net foo.org bar.com qux.com

/cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl img.gif img.gif img.gif img.gif http://harmless.org/index.html

. – p.1/??

SLIDE 6

CGI-Browser-CGI

geht.net foo.org bar.com qux.com

/cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl img.gif img.gif img.gif img.gif http://harmless.org/index.html

. – p.1/??

SLIDE 7

CGI-Browser-CGI

geht.net

spool

foo.org bar.com qux.com

/cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl img.gif img.gif img.gif http://harmless.org/index.html

. – p.1/??

SLIDE 8

CGI-Browser-CGI

303 Location http://geht.net/cgi−bin/img.pl?id=aswHu3gw49hh4...

geht.net

spool

foo.org bar.com qux.com

/cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl img.gif img.gif img.gif http://harmless.org/index.html

. – p.1/??

SLIDE 9

CGI-Browser-CGI

GET /cgi−bin/img.pl?id=aswHu3gw49hh4...

geht.net foo.org bar.com qux.com

/cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl img.gif img.gif img.gif http://harmless.org/index.html

. – p.1/??

SLIDE 10

CGI-Browser-CGI

http://harmless.org/index.html

geht.net

spool

foo.org bar.com qux.com

/cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl img.gif img.gif img.gif

. – p.1/??

SLIDE 11

CGI-Browser-CGI

....

geht.net foo.org bar.com qux.com

/cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl /cgi−bin/img.pl img.gif img.gif img.gif http://harmless.org/index.html

500 Content−Type: image/gif

. – p.1/??

SLIDE 12

CGI-Browser-CGI

qux.com geht.net

http://some.com/index.html http://some.com/index.html http://some.com/index.html http://some.com/index.html

foo.org bar.com

. – p.1/??

SLIDE 13

Same with Acks

cgi−bin/img.pl">

geht.net foo.org bar.com qux.com

http://some.com/index.html <frame src="http://foo.org/

. – p.2/??

SLIDE 14

Same with Acks

303 Location http://geht.net/cgi−bin/img.pl?id=9gXe0pl1f...

geht.net foo.org bar.com qux.com

http://some.com/index.html <frame src="http://foo.org/ cgi−bin/img.pl">

. – p.2/??

SLIDE 15

Same with Acks

GET /cgi−bin/img.pl?id=9gXe0pl1f...

geht.net foo.org bar.com qux.com

http://some.com/index.html <frame src="http://foo.org/ cgi−bin/img.pl"> . – p.2/??

SLIDE 16

Same with Acks

cgi−bin/img.pl?ack=0xd34..">

geht.net foo.org bar.com qux.com

http://some.com/index.html <img src="http://foo.org/

. – p.2/??

SLIDE 17

Same with Acks

GET /cgi−bin/img.pl?ack=0xd34...

geht.net foo.org bar.com qux.com

http://some.com/index.html <img src="http://foo.org/ cgi−bin/img.pl?ack=0xd34..">

. – p.2/??

SLIDE 18

Same with Acks

...

geht.net foo.org bar.com qux.com

http://some.com/index.html <img src="http://foo.org/ cgi−bin/img.pl?ack=0xd34.."> 500 Content−Type: image/gif . – p.2/??

SLIDE 19

Other ways

Cookies with Domain= .something.tld

(Broadcast)

. – p.3/??

SLIDE 20

Other ways

Cookies with Domain= .something.tld

(Broadcast)

Javascript:

. – p.3/??

SLIDE 21

Other ways

Cookies with Domain= .something.tld

(Broadcast)

Javascript:
submit prepared FORMs OnLoad

. – p.3/??

SLIDE 22

Other ways

Cookies with Domain= .something.tld

(Broadcast)

Javascript:
submit prepared FORMs OnLoad
Talking Frames ?

. – p.3/??

SLIDE 23

End Points

Have the receiver parse the HTML with a

script.

. – p.4/??

SLIDE 24

End Points

Have the receiver parse the HTML with a

script.

Steganography, but: Where on the Web are

images unique per request with sufficient entropy?

. – p.4/??

SLIDE 25

End Points

Have the receiver parse the HTML with a

script.

Steganography, but: Where on the Web are

images unique per request with sufficient entropy?

. – p.4/??

SLIDE 26

Properties

Hapless browsers transport the data,

indistinguishable from users of the PET

. – p.5/??

SLIDE 27

Properties

Hapless browsers transport the data,

indistinguishable from users of the PET

Established protocol (Firewalls, NAT,..)

. – p.5/??

SLIDE 28

Properties

Hapless browsers transport the data,

indistinguishable from users of the PET

Established protocol (Firewalls, NAT,..)
Anonymity set depends on popularity of web

pages

. – p.5/??