Here is an important question: "What gives Security Consultants the right to comment on how 'easy' it is to fix an XSS vulnerability?"
After all, it is not the Security Consultant's that:
1) needs to figure out:
- the root-cause analysis of the XSS reported?
- where it should be fixed?
- what is the REAL impact to the business?
- what are the side effects of applying the code changes?
2) has to make business case to fix it (and delaying XYZ feature)
3) has to actually fix the vulnerability
4) will be fired if the fixed is applied wrongly
5) will be the one that has the deal any side-effects created by the fixes
6) has to pay for it
Surely the only people qualified (and entitled) to make this 'easiness' assessment (i.e. of how 'easy' it is to fix a particular vulnerability) are the application developers and business owners!
Now think about how it must feel from the other side (i.e. the developers) when we (security consultants) tell them that it is 'easy' to fix what we just reported them.
And just to add insult to injury, we also like to tell them (the developers) that they need 'Training' (i.e. "...we think that you should go back to School and learn about security before you are allowed to write more code...")
It is 'easy' to say that that is 'easy' to fix...
... specially by the crowd whose responsibility ends when the problem/XSS is reported