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

Distill: Death to Cookies

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
220
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
330
RedDotRubyConf 2014: Magenta is a Lie - and other tales of abstraction
Avatar for Konstantin Haase rkh
0
970
Ancient City Ruby: Hack me, if you can!
Avatar for Konstantin Haase rkh
2
450
Boston I/O: Continuous Integration
Avatar for Konstantin Haase rkh
3
330
Steel City Ruby: Architecting Chaos
Avatar for Konstantin Haase rkh
4
960

Other Decks in Technology

See All in Technology
SSoT（Single Source of Truth）で「壊して再生」する設計
Avatar for かわうそ kawauso
2
420
PostgreSQL 18のNOT ENFORCEDな制約とDEFERRABLEの関係
Avatar for Yasuo Honda yahonda
1
210
MCPで決済に楽にする
Avatar for mu7889yoon / Yuta Nakamura mu7889yoon
0
170
Even G2 クイックスタートガイド（日本語版）
Avatar for vrshinobi vrshinobi1
0
190
Datadog で実現するセキュリティ対策 ~オブザーバビリティとセキュリティを 一緒にやると何がいいのか~
Avatar for Shuntaro Azuma a2ush
0
190
「できない」のアウトプット 同人誌『精神を壊してからの』シリーズ出版を 通して得られたこと
Avatar for comi comi190327
3
530
AWSで2番目にリリースされたサービスについてお話しします(諸説あります)
Avatar for Yuuki Yamashita yama3133
0
110
AWS DevOps Agent or Kiro の使いどころを考える_20260402
Avatar for モブエンジニア（Masaki Okuda） masakiokuda
0
140
20260326_AIDD事例紹介_ULSC.pdf
Avatar for ファインディ株式会社（イベント資料アップ用） findy_eventslides
0
380
Databricks Appsで実現する社内向けAIアプリ開発の効率化
Avatar for R-Miura r_miura
0
230
ブラックボックス化したMLシステムのVertex AI移行 / mlops_community_62
Avatar for Visional Engineering ＆ Design visional_engineering_and_design
1
260
Blue/Green Deployment を用いた PostgreSQL のメジャーバージョンアップ
Avatar for Ken Kato kkato1
1
230

Featured

See All Featured
The B2B funnel & how to create a winning content strategy
Avatar for Katarina Dahlin katarinadahlin
PRO
1
320
Applied NLP in the Age of Generative AI
Avatar for Ines Montani inesmontani
PRO
4
2.2k
Intergalactic Javascript Robots from Outer Space
Avatar for Vicent Martí tanoku
273
27k
[SF Ruby Conf 2025] Rails X
Avatar for Vladimir Dementyev palkan
2
880
More Than Pixels: Becoming A User Experience Designer
Avatar for Michelle Schulp Hunt marktimemedia
3
370
What Being in a Rock Band Can Teach Us About Real World SEO
Avatar for Ade Holder 427marketing
0
200
個人開発の失敗を避けるイケてる考え方 / tips for indie hackers
Avatar for panda_program panda_program
122
21k
The AI Search Optimization Roadmap by Aleyda Solis
Avatar for Aleyda Solis aleyda
1
5.5k
Optimising Largest Contentful Paint
Avatar for Harry Roberts csswizardry
37
3.6k
Design in an AI World
Avatar for tapps tapps
0
190
Future Trends and Review - Lecture 12 - Web Technologies (1019888BNR)
Avatar for Beat Signer signer
PRO
0
3.3k
Improving Core Web Vitals using Speculation Rules API
Avatar for Sergey Chernyshev sergeychernyshev
21
1.4k

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