How to insert a script (code snippet) inside html editor

Hi there!
Hope someone can help me with the problem that I can not insert a javascript (code snippet) in the html editor. The contao version is 2.9.5. I added <script> under system -> settings -> allowed HTML tags but it still does not show up on the frontpage. When I insert the code and press update it wraps the code with <![CDATA[ ... ]]> like WordPress does but when I look a bit further in the source code of the site I see that Google Maps (for example) gets wrapped with /*<![CDATA[*/ ... /*]]>*/ so it is somehow commented out. So the specific question is how can I add a code snippet inside the html editor?
Thanks in advance for your help. The customer I am working for is very impatient so I need to come up with a solution asap.
- Philipp

This CDATA is correct if your site is XHTML.