Source: https://moz.com/blog/how-to-defeat-duplicate-content-next-level
Google will not penalize you for duplicate content, but it can hurt your rankings. Here’s 3 ways to fix that.
Fixing duplicate content
1. 301 redirect – Identify which page has a higher authority, then apply a 301 redirect from the duplicate to the original page.
2. Rel=canonical – Simply add the canonical tag to the duplicate page to tell Google that it’s just a copy of the original page.
3. noindex, follow – This tells search engines to crawl the links but to not include the page in their indexes.