Website security upgrade needed - App project

Mobile app project description

I need some maintenance on a newly constructed website to fix some issues with security loopholes. Owing to the security risks referred to above, the site was recently infected with malware and needs to be addressed as soon as possible. While the site has been scanned to remove all the malware, the loopholes still remain to be addressed. The most important fixes needed are related to cross-site scripting vulnerability. The fixes are particularly important because site users can subscribe and some personal data is collected accordingly.

Detailed technical descriptions of the current situation can be provided.