As the complexity of applications and therefore of their testing process grows, the importance of automating the testing activity increases. The testing process includes test case generation, test sequencing, oracle construction, test execution and result interpretation. Automatic generation of test cases from formal specifications has received considerable attention. Relatively little work has been reported, however, on constructing oracles for supporting efficient and automatic execution of such test cases. We present a technique for constructing a CORBA-supported VDM oracle for black-box testing starting from a VDM-SL specification. This specification is used to automatically verify the results of operations implemented in a high-level programming language. We present a case study of the technique applied to a Java application for generic access control. The technique is applicable to any CORBA-compliant programming language.