Does the fix for the vulnerability involve adding a forgotten check?
A "forgotten check" can mean many things. It often manifests as the fix inserting an entire if-statement or a conditional to an existing if-statement. Or a call to a method that checks something.
Example of checks can include:
* null pointer checks
* check the current role, e.g. root
* boundary checks for a number
* consult file permissions
* check a return value