Upgrade to Pro — share decks privately, control downloads, hide ads and more …

Distill: Death to Cookies

Sponsored · Ship Features Fearlessly Turn features on and off without deploys. Used by thousands of Ruby developers. →
Avatar for Konstantin Haase Konstantin Haase
August 09, 2013
Technology
1.2k
7

Distill: Death to Cookies

Avatar for Konstantin Haase

Konstantin Haase

August 09, 2013

More Decks by Konstantin Haase

See All by Konstantin Haase
RubyConf Philippines 2017: Magenta is a Lie
Avatar for Konstantin Haase rkh
0
230
How We Replaced Salary Negotiations with a Sinatra App
Avatar for Konstantin Haase rkh
17
4.3k
HTTP (RubyMonsters Edition)
Avatar for Konstantin Haase rkh
5
1.2k
GCRC 2015: Abstract Thoughts on Abstract Things
Avatar for Konstantin Haase rkh
1
390
Frozen Rails: Magenta - The Art Of Abstraction
Avatar for Konstantin Haase rkh
3
340
RedDotRubyConf 2014: Magenta is a Lie - and other tales of abstraction
Avatar for Konstantin Haase rkh
0
990
Ancient City Ruby: Hack me, if you can!
Avatar for Konstantin Haase rkh
2
460
Boston I/O: Continuous Integration
Avatar for Konstantin Haase rkh
3
340
Steel City Ruby: Architecting Chaos
Avatar for Konstantin Haase rkh
4
980

Other Decks in Technology

See All in Technology
Javaで学ぶSOLID原則
Avatar for Negima negima
1
270
GoとSIMDとWasmの今。
Avatar for asuka askua
3
490
【Gen-AX】20260530開催_JJUG CCC 2026 Spring
Avatar for Gen-AX株式会社 genax
0
400
Ruby::Boxでできること、Refinementsでできること
Avatar for Tomohiro Hashidate joker1007
3
380
AI Adaptable なテストを整える工夫 / Ways to Make Your Tests AI-Adaptable
Avatar for 株式会社ビットキー / Bitkey Inc. bitkey
PRO
2
210
Sony_KMP_Journey_KotlinConf2026
Avatar for ソニー株式会社 sony
2
210
エンジニアは生成AIと どのように向き合うべきか？ ことばの意味という観点から
Avatar for Hitomi Yanaka verypluming
3
340
運用を見据えたAIエージェント設計実践
Avatar for amacbee amacbee
1
2.4k
Spring Boot における​ AOT Cache 活用テクニックと​ 起動時間改善事例​
Avatar for NTTドコモソリューションズ　Java担当 ntt_dsol_java
0
200
タクシーアプリ『GO』の実践的データ活用
Avatar for GO Inc. dev mot_techtalk
2
110
Cloud Run のアップデート 触ってみる＆紹介
Avatar for Gre212 gre212
0
300
noUncheckedIndexedAccess、3時間、1万円。 / noUncheckedIndexedAccess, 3 Hours, 10,000 JPY.
Avatar for 株式会社カオナビ kaonavi
1
190

Featured

See All Featured
Leveraging Curiosity to Care for An Aging Population
Avatar for Cassini Nazir cassininazir
1
260
Intergalactic Javascript Robots from Outer Space
Avatar for Vicent Martí tanoku
273
27k
Balancing Empowerment & Direction
Avatar for Lara Hogan lara
6
1.1k
AI Search: Implications for SEO and How to Move Forward - #ShenzhenSEOConference
Avatar for Aleyda Solis aleyda
1
1.3k
Code Reviewing Like a Champion
Avatar for maltzj maltzj
528
40k
What Being in a Rock Band Can Teach Us About Real World SEO
Avatar for Ade Holder 427marketing
0
240
A Modern Web Designer's Workflow
Avatar for Chris Coyier chriscoyier
698
190k
We Analyzed 250 Million AI Search Results: Here's What I Found
Avatar for Josh Blyskal joshbly
1
1.3k
Avoiding the “Bad Training, Faster” Trap in the Age of AI
Avatar for Mike Taylor tmiket
0
170
Java REST API Framework Comparison - PWX 2021
Avatar for Matt Raible mraible
34
9.3k
Paper Plane (Part 1)
Avatar for Katie Cordina Lindsey katiecoart
PRO
0
8.4k
Producing Creativity
Avatar for Steve Smith orderedlist
PRO
348
40k

Transcript

  1. Death to Cookies Konstantin Haase @konstantinhaase

  2. story time

  3. None
  4. None
  5. None

  6. once upon a time

  7. None
  8. None

  9. Recipetastic™

  10. None
  11. None

  12. Bob Alice

  13. Bob Alice

  14. Bob Alice Eve

  15. Bob Alice Mallet

  16. problem solved

  17. None

  18. POST /login HTTP/1.1 Host: www.recipetast.ic Content-Length: 44 [email protected]& password=st0p%20Motion

  19. HTTP/1.1 200 OK Content-Type: text/html Set-Cookie: user=bob <html> ...

  20. GET / HTTP/1.1 Host: www.recipetast.ic Cookie: user=bob

  21. Guessing

  22. None
  23. None
  24. None

  25. HTTP/1.1 200 OK Content-Type: text/html Set-Cookie: user=bob Set-Cookie: pwd=... <html>

    ...

  26. GET / HTTP/1.1 Host: www.recipetast.ic Cookie: user=bob,pwd=...

  27. GET / HTTP/1.1 Host: www.recipetast.ic Cookie: user=bob,pwd=... Basic Auth, just

    with cookies

  28. HTTP/1.1 200 OK Content-Type: text/html Set-Cookie: user=bob Set-Cookie: token=... <html>

    ...
  29. None

  30. XSS Cross Site Scripting

  31. None

  32. can read cookie and send it somewhere

  33. None

  34. HTTP/1.1 200 OK Content-Type: text/html Set-Cookie: user=bob; HttpOnly <html> ...

  35. None

  36. can read (and write) recipes

  37. None

  38. sanitize all user input

  39. Content Security Policy

  40. None

  41. CSRF Cross Site Request Forgery

  42. Is this awesome, y/n?

  43. None

  44. GET /create?… HTTP/1.1 Host: www.recipetast.ic Cookie: user=alice

  45. GET /create?… HTTP/1.1 Host: www.recipetast.ic Cookie: user=alice Deadly cookies!

  46. None

  47. GET, HEAD, OPTIONS, TRACE PUT, DELETE, LINK, UNLINK POST, PATCH

  48. 1 2 PUT / 2 PUT / 2 Repeatable! :)

    State change! :( Deterministic! :) https://speakerdeck.com/rkh/we-dont-know-http

  49. GET, HEAD, OPTIONS, TRACE PUT, DELETE, LINK, UNLINK POST, PATCH

  50. None
  51. None
  52. None

  53. POST /create HTTP/1.1 Host: www.recipetast.ic Cookie: user=alice ...

  54. POST /create HTTP/1.1 Host: www.recipetast.ic Cookie: user=alice ... Deadly cookies!

  55. None

  56. POST /create HTTP/1.1 Host: www.recipetast.ic Referer: http://awesome- website.com/ Cookie: user=alice

  57. POST /create HTTP/1.1 Host: www.recipetast.ic Referer: http://awesome- website.com/ Cookie: user=alice

    [sic]
  58. None
  59. None

  60. Referer is not set for FTP or HTTPS referrers

  61. Referer can be spoofed by outdated flash plugin

  62. None

  63. POST /create HTTP/1.1 Host: www.recipetast.ic Origin: http://awesome- website.com Cookie: user=alice

  64. None
  65. None

  66. Not supported by older browsers

  67. Origin can probably be spoofed by outdated flash plugin

  68. None

  69. HTTP/1.1 200 OK Content-Type: text/html Set-Cookie: csrf_token=XXX

  70. None
  71. None

  72. Cheating Same Origin

  73. HTTP/1.1 200 OK Content-Type: application/json

  74. An attacker could just load it, right?

  75. AJAX can only load from the same origin (or CORS)

  76. None

  77. seems harmless

  78. In JavaScript, you can override the array constructor.

  79. https://github.com/rkh/json-csrf

  80. None

  81. Never serve JSON that has an array at top level

    (or don’t use cookies)
  82. None

  83. VBScript did not fully implement Same Origin

  84. None

  85. Block Internet Explorer before IE9

  86. Block Internet Explorer before IE9

  87. require CSRF token for all AJAX requests

  88. None

  89. Are we doing good so far?

  90. None

  91. Can we trust a cookie?

  92. DNS cache poisoning

  93. Can we trust the browser?

  94. Can we trust browser plugins?

  95. None
  96. None

  97. Signed Cookies

  98. Encrypted Cookies

  99. None

  100. Eaves- dropping

  101. encrypting cookies does not help

  102. None
  103. None
  104. None

  105. attacker cannot parse cookie from stream

  106. None

  107. Or can they?

  108. BEAST Browser Exploit Against SSL/ TLS

  109. decrypts TLS 1.0 streams via injected JavaScript

  110. None

  111. fixed in TLS 1.1

  112. force recent browser

  113. don’t allow TLS 1.0

  114. None

  115. CRIME Compression Ratio Info-leak Made Easy

  116. SSL has built-in compression

  117. GET /?user=alice HTTP/1.1 Host: www.recipetast.ic Cookie: user=bob GET /?user=bob HTTP/1.1

    Host: www.recipetast.ic Cookie: user=bob better compression
  118. None

  119. update your browser

  120. turn off SSL compression

  121. append random number of bytes to response

  122. None

  123. BREACH Browser Reconnaissance and Exfiltration via Adaptive Compression of Hypertext

  124. like CRIME, but for the response

  125. attack the CSRF token, not the cookie

  126. inject something in the response http://www.recipetast.ic/search?q=XXX

  127. None

  128. mask CSRF tokens differently in every response (Rails PR pending)

  129. don’t use CSRF tokens

  130. None

  131. Do you think about all this when you build an

    app?

  132. Next attack vector around the corner?

  133. None

  134. Alternatives

  135. IP address

  136. Session ID in URL

  137. None

  138. Custom Authorization header

  139. None

  140. Store value in Local Storage

  141. Needs JavaScript :(

  142. Works well with PJAX/ Turbo Links like setups

  143. None

  144. New Browser Concepts?

  145. None

  146. @konstantinhaase [email protected] rkh.im