Drupal security modules

Base security modules for drupal:

  1. Login security http://drupal.org/project/login_security
  2. Password policy https://www.drupal.org/project/password_policy
  3. Update manager https://www.drupal.org/documentation/modules/update
  4. Captcha https://www.drupal.org/project/captcha
  5. Flood Control https://www.drupal.org/project/flood_control
  6. Secure Pages Hijack Prevention    https://www.drupal.org/project/securepages_prevent_hijack
  7. XFS (cross frame scripting) https://www.drupal.org/project/seckit
  8. Idle Session Timeout https://www.drupal.org/project/autologout
  9. Concurrent Sessions https://www.drupal.org/project/session_limit
  10. ACL https://www.drupal.org/project/acl
  11. Two-factor Authentication (TFA) https://www.drupal.org/project/tfa
  12. Paranoia https://www.drupal.org/project/paranoia
  13. Coder https://www.drupal.org/project/coder
  14. Security Review https://www.drupal.org/project/security_review
  15. SpamSpan filter https://www.drupal.org/project/spamspan

source: http://resources.infosecinstitute.com/15-security-modules-for-drupal-to-make-website-secure/