JBoss Drools, Red Hat JBoss BRMS before 6.0.1, and Red Hat JBoss BPM Suite before 6.0.1 allows remote authenticated users to execute arbitrary Java code via a (1) MVFLEX Expression Language (MVEL) or (2) Drools expression.
Improper Control of Generation of Code The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.