Invicti identified a Remote Code Evaluation (RoR) by capturing a DNS A request, which occurs when input data is run as code.
An attacker can send a specially crafted XML request to the application containing an embedded YAML-encoded object. Rails will parse the XML and load the objects from YAML. In the process, arbitrary Ruby code sent by the attacker may be executed (depending on the type and structure of the injected objects).
- Disable XML entirely
- Remove YAML / Symbol support from XML parsing