SA-CORE-2018-002 Drupal core vulnerability: We've got you covered

An hour ago the SA-CORE-2018-002 critical Drupal vulnerability was disclosed. It was announced a week ago PSA-2018-001. That allowed us to gather our technical team and make sure we can develop and deploy a mitigation to all our clients immediately as the issue is made known.

If you're not running on Platform.sh, please stop reading this post and go update your Drupal site to version 8.5.1 / 8.4.9 / 8.3.8 / 7.58 right now. We're serious; upgrade first and ask questions later.

If you are running on Platform.sh: You're safe and can continue reading... then upgrade.

The vulnerability (also referred to as CVE-2108-7600) affects the vast majority of Drupal 6.x, 7.x and 8.x sites and allows arbitrary remote code execution that allow anonymous remote users to take full control of any affected Drupal site prior to 8.5.1 / 8.4.9 / 8.3.8 / 7.58.

The same issue is present in Backdrop CMS installations prior to 1.9.3.

If your Drupal site is not hosted on Platform.sh we encourage you to immediately update all your Drupal sites to 8.5.1 / 7.58 or to take your site offline. This is serious and trivially exploitable. You can expect automated attacks to appear within hours at most. If you are not on Platform.sh or another provider that has implemented a mitigation your site will be hacked. This is as critical as the notorious “DrupaGeddon” episode from three and a half years ago.

If you are hosting on Platform.sh...

Platform.sh is pleased to announce all Drupal sites hosted on all our regions and all our plans are automatically safe from this attack.

Platform.sh has many security layers that make attacks such as this much harder than on comparable services. Starting from our read-only hosts and our read-only containers, through our auditable and reproducible build-chain, and static-analysis based protective block.

In response to this latest vulnerability, we've taken two important steps:

1. We've added a new rule to our Web Application Firewall (WAF) on all regions and on all Enterprise clusters that detects and blocks requests trying to exploit this latest attack vector, even if your site hasn't been updated. (But still, please update.)

2. We are adding a check to our protective block to prevent deployment of affected Drupal versions. If you try to push an insecure Drupal version our system will flag it for you and warn you that you are pushing known-insecure code. Please update your code base as soon as possible.

As a client if you need any further assistance or want more information about the vulnerability, how it may affect you, and our mitigation strategy don’t hesitate to contact support. We have set our WAF to an especially aggressive stance for now and this may result in some users seeing a "400 Bad Request" message in some edge cases for legitimate traffic. If you experience this, please contact our support immediately they will be able to help.