Language: Go
Label: vulnerable
CWE: CWE-22 \u2014 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

Code:
func BytesToFile(filePath string, data []byte) error {
	exist, _ := IsPathExist(filePath)
	if !exist {
		if err := CreateFile(filePath); err != nil {
			return err
		}
	}
	return ioutil.WriteFile(filePath, data, 0644)
}