Drupal released security updates for Drupal 7, 8.5 and 8.6 that address two “critical” security vulnerabilities that could be exploited for arbitrary code execution.
The first vulnerability could be exploited by a remote attacker to execute arbitrary PHP code. The flaw resides in the phar stream wrapper implemented in PHP and is related to the way it handles untrusted phar:// URIs.
“A remote code execution vulnerability exists in PHP’s built-in phar stream wrapper when performing file operations on an untrusted phar:// URI. ” reads the security advisory.
“Some Drupal code (core, contrib, and custom) may be performing file operations on insufficiently validated user input, thereby being exposed to this vulnerability, This vulnerability is mitigated by the fact that such code paths typically require access to an administrative permission or an atypical configuration.”