The vulnerability stems from improper validation of user identity fields in XML workflow definitions. Based on Oozie's architecture:

1. SubmitXCommand.execute is the workflow submission entry point that would process XML input
2. WorkflowAppService handles XML parsing and workflow definition processing
3. XConfiguration.get is used throughout to access configuration properties

While the exact patch details are unavailable, these functions form the core XML processing chain that would handle user impersonation parameters. The vulnerability would manifest when these functions process malicious 'user.name' values without validating against the authenticated user context.