Title tags all same for CMS made pages. How to fix??

I hired someone to add a CMS to an existing website and now all the pages created by the CMS or pages having this kind of url: http://www.website.com/page.php?page=5 are now ALL having the exact same Title tags, meta tags, meta descriptions etc.

I am in urgent need of a way to fix this! I cannot do SEO properly with all pages having the EXACT same information. Please help!

Thank you in advance