The vulnerability stems from unencrypted storage of credentials in the plugin's global configuration file. Jenkins plugins typically use a configure() method in their Builder/Descriptor classes to handle configuration persistence. The high confidence in ElOyenteBuilder.configure comes from: 1) Standard Jenkins plugin architecture patterns 2) Direct reference to the vulnerable file name matching the plugin's FQCN 3) The CWE-522 pattern matching unencrypted credential persistence. The setPassword method is inferred as medium confidence since password handling setters are typically involved in credential storage flows, though without seeing the actual code we can't confirm implementation details.