Vulnerable code?

Okay, after leaving one of my favorite sonic fan forums. I got curious and started searching in the source code of some pages. In a page I found this code in this link:

http://Not_giving_site.org/index.php?act=boardrules

var q = unescape(location.search.substring(1)).split(/[=&]/);
for (var j=0; j<q.length; j+=2) {
if (q[j] == name) {
return q[j+1]```

It's javascript yes. The whole page is created in javascript. Is this code vulnerable? and is it safe to code a whole page in javascript?

javascript is client side, not server side. manipulating the DOM wont be a direct root to attack a site, so in theory its reasonably safe. but it depends how your websites backend is put together.

it all depends on the situation.

if the whole site is controlled by javascript you might make the assumption that they do alot of the validation with javascript. You could modify their code or use something like the tamperdata FF extension to try and exploit their sql database or xss the pages. just a thought.