This indicates an attack attempt to exploit a remote Code Execution in Ruby On Rails.
The vulnerability is due to an error in the XML processor. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application via a crafted XML file.
Ruby on Rails prior to 2.3.15
Ruby on Rails prior to 3.0.19
Ruby on Rails prior to 3.1.10
Ruby on Rails prior to 3.2.11
System Compromise: Remote attackers can gain control of vulnerable systems.
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