View pdf from attachments page renders background image rotated in pdf.

Summary

Importing PDF file to the Confluence, and checking the content of that PDF from "view" option in attachments of that page, will show images in background of that PDF rotated vertically.

Steps to Reproduce

1. Import attached PDF Atlassian Certified JIRA Administrator certificate.pdf to Confluence page.
2. Go to attachments from that page.
3. Click "view" on that attachment

Expected Results

1. View PDF page with normal images, as in the actual PDF.

Actual Results

1. Background images are rotated vertical.
2. 

Workaround

No known workaround at the moment.