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

Distill: Death to Cookies

Sponsored · SiteGround - Reliable hosting with speed, security, and support you can count on. →
Avatar for Konstantin Haase Konstantin Haase
August 09, 2013
Technology
7
1.2k

Distill: Death to Cookies

Avatar for Konstantin Haase

Konstantin Haase

August 09, 2013
Tweet

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
380
Frozen Rails: Magenta - The Art Of Abstraction
Avatar for Konstantin Haase rkh
3
320
RedDotRubyConf 2014: Magenta is a Lie - and other tales of abstraction
Avatar for Konstantin Haase rkh
0
960
Ancient City Ruby: Hack me, if you can!
Avatar for Konstantin Haase rkh
2
440
Boston I/O: Continuous Integration
Avatar for Konstantin Haase rkh
3
320
Steel City Ruby: Architecting Chaos
Avatar for Konstantin Haase rkh
4
950

Other Decks in Technology

See All in Technology
Bill One 開発エンジニア 紹介資料
Avatar for Sansan, Inc. sansan33
PRO
4
17k
入社1ヶ月でデータパイプライン講座を作った話
Avatar for Yuta Ozaki waiwai2111
1
220
GSIが複数キー対応したことで、俺達はいったい何が嬉しいのか？
Avatar for Makky12 smt7174
3
140
クレジットカード決済基盤を支えるSRE - 厳格な監査とSRE運用の両立 (SRE Kaigi 2026)
Avatar for capytan capytan
6
2.4k
学生・新卒・ジュニアから目指すSRE
Avatar for Hiroya Onoe hiroyaonoe
2
530
分析画面のクリック操作をそのままコード化 ！ エンジニアとビジネスユーザーが共存するAI-ReadyなBI基盤
Avatar for ikumi ikumi
1
230
Context Engineeringが企業で不可欠になる理由
Avatar for Hirosato Gamo hirosatogamo
PRO
2
290
Sansan Engineering Unit 紹介資料
Avatar for Sansan, Inc. sansan33
PRO
1
3.8k
MySQLのJSON機能の活用術
Avatar for mikoma ikomachi226
0
150
MCPでつなぐElasticsearchとLLM - 深夜の障害対応を楽にしたい / Bridging Elasticsearch and LLMs with MCP
Avatar for Sashimimochi sashimimochi
0
140
Embedded SREの終わりを設計する　「なんとなく」から計画的な自立支援へ
Avatar for SansanTech sansantech
PRO
3
2.1k
2026年、サーバーレスの現在地 -「制約と戦う技術」から「当たり前の実行基盤」へ- /serverless2026
Avatar for Serverless Operations slsops
2
200

Featured

See All Featured
Put a Button on it: Removing Barriers to Going Fast.
Avatar for kastner kastner
60
4.2k
Applied NLP in the Age of Generative AI
Avatar for Ines Montani inesmontani
PRO
4
2k
SEO in 2025: How to Prepare for the Future of Search
Avatar for Michael King ipullrank
3
3.3k
Automating Front-end Workflow
Avatar for Addy Osmani addyosmani
1371
200k
What the history of the web can teach us about the future of AI
Avatar for Ines Montani inesmontani
PRO
1
420
Skip the Path - Find Your Career Trail
Avatar for Mark Kilby mkilby
0
52
How People are Using Generative and Agentic AI to Supercharge Their Products, Projects, Services and Value Streams Today
Avatar for Helen Beal helenjbeal
1
110
Hiding What from Whom? A Critical Review of the History of Programming languages for Music
Avatar for Tomoya Matsuura tomoyanonymous
2
410
Fight the Zombie Pattern Library - RWD Summit 2016
Avatar for Marcelo Somers marcelosomers
234
17k
コードの90%をAIが書く世界で何が待っているのか / What awaits us in a world where 90% of the code is written by AI
Avatar for r-kagaya rkaga
60
42k
Sharpening the Axe: The Primacy of Toolmaking
Avatar for Bryan Cantrill bcantrill
46
2.7k
The Illustrated Guide to Node.js - THAT Conference 2024
Avatar for David Neal reverentgeek
0
250

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