The vulnerability explicitly involves unencrypted storage of tokens in job config.xml files. Jenkins plugins typically serialize job configuration data (like tokens) using XStream or similar frameworks. The functions responsible for defining/storing the token field (e.g., a setter or builder class) and the serialization/deserialization logic (configure method) are the most likely candidates. While no direct code was provided, the pattern matches Jenkins plugin vulnerability paradigms (CWE-256/CWE-522), and the plugin's lack of encryption in config.xml implies insecure handling in these core configuration functions.