The vulnerability stems from insecure default configuration rather than specific function implementations. The advisory indicates the default file upload handling lacks proper validation, but no code examples, commit diffs, or function names are provided in the vulnerability details. While core file upload processing functions (e.g., file type validation routines) are likely involved, the absence of concrete technical details about the implementation prevents high-confidence identification of specific vulnerable functions. The CWE-1188 classification confirms this is a default configuration/resource initialization issue rather than a flaw in a specific function's logic.