The vulnerability stems from insecure usage of JDBC connections (particularly with MySQL drivers) rather than specific functions in Apache Jena SDB's codebase. The advisory indicates the root cause is improper handling of JDBC URL parameters (e.g., failing to disable 'autoDeserialize') and deserialization of untrusted data from database responses. However, no specific functions or code paths in Jena SDB are explicitly mentioned in the provided vulnerability details, commit diffs, or patch information. The vulnerability manifests through integration patterns with vulnerable JDBC drivers rather than identifiable functions within the Jena SDB package itself. This analysis is limited by the lack of code-specific references in the provided advisories and the EOL status of Jena SDB preventing patch analysis.