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Final race-condition-in-the-web

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Final race-condition-in-the-web

  1. 1. Race Condition Attacks in Web Applications gamma95[at]gmail[dot].com
  2. 2. Breaking news
  3. 3. About me
  4. 4. About me $g4mm4 === $gamma95 ● Penetration tester ● Bugs hunter ● Full time Internet Troll
  5. 5. About the talk● What is race condition?● Race conditions in the web applications● Prevention● Demo● References● Q&A
  6. 6. What is race condition?● A race condition or race hazard is a type of flaw in an electronic or software system where the output is dependent on the sequence or timing of other uncontrollable events● Race conditions can occur in electronics systems, especially logic circuits, and in computer software, especially multithreaded or distributed programs.
  7. 7. in Electronics● ∆t1 and ∆t2 represent the propagation delays of the logic elements.● When the input value (A) changes, the circuit outputs a short spike of duration (∆t1+∆t2) - ∆t2 = ∆t1
  8. 8. In Computer Software (file system, networking ...)
  9. 9. in Web Applications: Hit Counter
  10. 10. in Web Applications: Hit Counter
  11. 11. Tell me why?
  12. 12. Tell me why?
  13. 13. in Web Applications: Online Banking
  14. 14. in Web Applications: Online Banking
  15. 15. D3m0
  16. 16. Prevention
  17. 17. Semaphore
  18. 18. System V Semaphore PHP is compiled with --enable-sysvsem
  19. 19. LFI with phpinfo()● What is LFI? Local File Inclusion (also known as LFI) is the process of including files on a server through the web browser. This vulnerability occurs when a page include is not properly sanitized, and allows directory traversal characters to be injected
  20. 20. LFI with phpinfo()● Why PHPInfo()? The output of the PHPInfo() script contains the values of the PHP Variables, including any values set via _GET, _POST or uploaded _FILES.
  21. 21. How to win the race ?
  22. 22. D3m0
  23. 23. References● Practical Race Condition Vulnerabilities in Web Applications https://defuse.ca/race-conditions-in-web-applications.htm● "LFI with phpinfo() assistance" http://www.insomniasec.com/publications/LFI With PHPInfo Assistance.pdf● Nghệ thuật tận dụng lỗi phần mềm http://bluemoon.com.vn/books/8935048992197.html
  24. 24. Questions?
  25. 25. Thats all folks!

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