Add link to CVE

Author: mattiasgeniar

found_on_drupal/found_due_to_cve_2018_7600/README.md

@@ -2,6 +2,8 @@
 
 These are some of the examples we found on compromised Drupal installs at [Nucleus](https://www.nucleus.be/en/).
 
+They are the direct result of [CVE-2018-7600](https://www.drupal.org/sa-core-2018-002), a remote code execution vulnerability in Drupal.
+
 The pattern:
 
 - search.php, dump.php & wp-post.php: same filename everywhere