Backdrop core - Critical - Arbitrary PHP code execution - SA-CORE-2019-002
A remote code execution vulnerability exists in PHP's built-in phar stream wrapper when performing file operations on an untrusted phar:// URI.
Some Backdrop 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.
.phar added to dangerous extensions list
The .phar file extension has been added to Backdrop's dangerous extensions list, which means that any such file uploaded to a Backdrop file field will automatically be converted to a text file (with the .txt extension) to prevent it from being executed. This is similar to how Backdrop handles file uploads with a .php extension.
Another SA was released today, see also:
- Backdrop core versions prior to 1.12.1 and 1.11.5