Web server configuration to mitigate Drupal SA-CORE-2018-002. Written by trusted sources. Patch your sites!!

apache-SA-CORE-2018-002.conf

# Apache configuration to block attempts to exploit the SA
# If using Aegir, you can put this file in /var/aegir/config/server_master/apache/post.d/SA-CORE-2018-002.conf
<IfModule mod_rewrite.c>
  RewriteEngine On
  RewriteCond %{QUERY_STRING} (.*)(23value|23default_value|element_parents=%23)(.*) [NC]
  RewriteCond %{REQUEST_METHOD} POST [NC]
  RewriteRule ^.*$  - [R=403,L]
</IfModule>

nginx-SA-CORE-2018-002.conf

# NGINX configuration to block attempts to exploit the SA
# If using Aegir, you can put this file in /var/aegir/config/server_master/nginx/post.d/SA-CORE-2018-002.conf
set $rce "ZZ";
if ( $query_string ~* (23value|23default_value|element_parents=%23) ) {
  set $rce "A";
}
if ( $request_method = POST ) {
  set $rce "${rce}B";
}
if ( $rce = "AB" ) {
  return 403;
}