The vulnerability stems from improper XML parser configuration (CWE-611). The advisory explicitly states the plugin doesn't disable XXE protections. While exact function names aren't provided, the core vulnerability pattern matches XML parsing functions handling user-controlled input without security flags like FEATURE_SECURE_PROCESSING or disallowing DTDs. The ConfigStorage class is a logical location for XML configuration handling in a 'Storable Configs' plugin. The high confidence comes from the direct match between the described vulnerability and the standard XXE attack pattern in XML parsing functions.