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WordPress Security 101 – WordCamp Finland 2016 presentation by Otto Kekäläinen (extended edition)


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Extended edition of presentation about "WordPress security: what is important and what is not" held at WordCamp Finland, April 15th 2016 by Otto Kekäläinen (from /

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WordPress Security 101 – WordCamp Finland 2016 presentation by Otto Kekäläinen (extended edition)

  1. 1. @ottokekalainen WORDPRESS SECURITY 101 what is important – and what is not WordCamp Finland 2016 Otto Kekäläinen
  2. 2. @ottokekalainen Definition of information security 1. Confidentiality 2. Integrity 3. Availability
  3. 3. @ottokekalainen You must keep your WordPress site secure
  4. 4. @ottokekalainen Potential consequences ● Corrupted orders database: webshop unable to ship anything or resolve payments ● Leaked customer database: angry customers, lawsuit for neglect of privacy laws ● Visitors get redirected to shady sites: lost reputation, marketing budget goes in vain ● Site spreads malware: Google might detect and ban from showing up in search results ● Site sends spam: could become blacklisted and legit email stops working
  5. 5. @ottokekalainen “But my site is not important!” Your site can be used to mount further attacks! If you have clearly neglected the maintenance of your own site, you could be held partly liable for attacks on other sites.
  6. 6. @ottokekalainen What is really important in keeping your WordPress site secure?
  7. 7. @ottokekalainen Avenues of unauthorized access: 1. Leaked passwords 2. Software vulnerabilities
  8. 8. @ottokekalainen Leaked passwords
  9. 9. @ottokekalainen Remember password hygiene
  10. 10. @ottokekalainen HTTPS, SFTP, SSH Never submit passwords over an unencrypted connection!
  11. 11. @ottokekalainen 1. Your server needs to support HTTPS 2. Enforce in wp-config.php with: define('FORCE_SSL_ADMIN', true); Enforce HTTPS in WordPress
  12. 12. @ottokekalainen Use captcha to avoid robot users Google reCaptcha recommended
  13. 13. @ottokekalainen Software vulnerabilities
  14. 14. @ottokekalainen 1. Minimize the attack surface by minimizing the amount of software you have 2. For the software you really need, make sure you have updated to latest releases Minimize vulnerabilities
  15. 15. @ottokekalainen How secure is the WordPress core? Security bugs per 1000 lines of code written All time: 0,1 (204 CVE entries per 2,1 million lines of code) In 2015: 0,05 (11 CVE entries per 236 000 lines of code)
  16. 16. @ottokekalainen WordPress core is secure.
  17. 17. @ottokekalainen The problem is the plugins.
  18. 18. @ottokekalainen Combined core, plugin and theme vulnerability database:
  19. 19. @ottokekalainen Example case: Mossack Fonseca aka Panama papers ● The site was running WordPress ● Unauthorized access of WP lead to unauthorized access of MS Exchange email server on internal network and other sites at * ● The intruders most likely came through an old and insecure version of the Revolution Slider plugin. ○ Well known vulnerability, even has a patch as a separate plugin (https: // as Revolution Slider itself is not available at
  20. 20. @ottokekalainen Example case: Mossack Fonseca aka Panama papers ● Case analysis at fonseca-breach-vulnerable-slider-revolution/
  21. 21. @ottokekalainen WP plugin review guidelines for capitalists* If the logo is red and name contains revolution, don’t install it on your system! * a small dose of parody can’t hurt?
  22. 22. @ottokekalainen If you run your own server Also remember to harden and keep updated ● operating system ● web server ● database server ● PHP environment
  23. 23. @ottokekalainen Install only from trusted sources. Avoid random 3rd party repositories that don’t have any maintenance policy.
  24. 24. @ottokekalainen Don’t waste time on ● removing generator meta or hiding version numbers ● hiding login errors ● changing wp-admin location ● removing readme.html or other files ● disabling xmlrpc Only for WP geeks who love to research the pros and cons. For normal users WordPress default settings are secure.
  25. 25. @ottokekalainen False sense of security: feels like a lot has been done when really very little has.
  26. 26. @ottokekalainen Scan results require interpretation. Recommended only for professionals. Security plugins are not the solution
  27. 27. @ottokekalainen The only recommended ones: WPScan and Google Webmaster Tools Almost no false positives and no business model based on spreading fear.
  28. 28. @ottokekalainen Protection against DDOS What if the problem is not unauthorized access but the lack of authorized access?
  29. 29. @ottokekalainen Denial of service attacks Detect, withstand and block ● high performance servers and good caching ● detect repeated offenders and block at network level ○ e.g. failtoban + iptables DDOS is a constant race of new techniques of attack and defence. Try to find a good hosting provider that takes care of DDOS at least on the network level.
  30. 30. @ottokekalainen Backup and recovery Because some day, sooner or later, everything else fails.
  31. 31. @ottokekalainen Backup guidelines1/2 Make sure your backup system meets these requirements ● automatic: not dependant on human action ● complete: both files and database ● incremental with a history: at least 30 days ● frequent: daily is good
  32. 32. @ottokekalainen List continues.. ● offsite: in case access to the original site is lost ● pull, not push: original site should not have access to the backups, otherwise an attacker can delete both the original site and all backups Personal favourite: mysqldump + rdiff-backup over SSH Backup guidelines1/2
  33. 33. @ottokekalainen Once more with a feeling
  34. 34. @ottokekalainen 1. Always follow password hygiene. 2. Use captchas to stall robot users. 3. Use HTTPS (and SFTP and SSH) – never submit passwords in plain text on any network connection. 4. Remove unnecessary software to reduce attack surface. 5. Keep WordPress plugins and all other software too updated to have all known vulnerability fixes installed. 6. Install software and update only from trusted sources. 7. Have a good backups system in place. 8. Choose a good service provider and trust them to take care of the rest. WordPress security 101
  35. 35. @ottokekalainen Thank You! Visit https://wp-palvelu. fi/blogi for more tips (in Finnish)