If you're using Acrobat, you can use the Crop Pages tool under the Edit PDF toolbar. Use the tool to draw a bounding box around the content you want to keep.
In the Crop Pages dialogue, set your page range to "All"
Ta-daa, your document is cropped :)
You can do a similar thing in InDesign, by placing your PDF across multiple pages as graphics, then changing the page size for the document.
To paste multiple pages of the PDF, make sure you have "Show Import Options" checked in your Place dialogue box…
…then set Pages to "All" to load all the pages into your Place cursor as individual graphics, so you can place them one-by-one. Make sure each one is centred on the page.
Now set your Page Size to the size of the content you want to keep. It may help to draw a box around the content to get the size…
…then use the measurements of the box to set the page size in the Document Setup dialogue.
Now you have a document without a white border, ready to export as a new PDF :)
It's certainly quicker with Acrobat, but the InDesign method can also be useful. Hope this helps!