There are different ways to identify accurate weakness mapping(s) for a CVE Record. While one may be easier for some users versus another, a best practice is to verify your intended mapping with a colleague with slightly different skills and experience than you. Before starting, be sure to review the example root cause mappings. Understanding the process and reasoning behind each example will help when using any of the following methods.
Keyword Search Method
CWE has a search feature available on the home page of the CWE website, illustrated below.
Keyword Search Method