The vulnerability stems from improper application of security advisors during proxy creation when using @AuthorizeReturnObject or AuthorizationAdvisorProxyFactory. The primary suspect is AuthorizationAdvisorProxyFactory.createProxy, which handles proxy wrapping but fails to ensure method security advice is applied in environments with competing proxy creators (AnnotationAwareAspectJAutoProxyCreator) and FactoryBeans. The medium-confidence entry for AuthorizeReturnObjectAspect reflects its role in annotation processing, though the exact failure mechanism is less explicitly documented. Both components are central to the described attack vector where security annotations become ineffective on wrapped objects.