Version 24 is an Extended Support Release (ESR). Mozilla provides about one year support compared to 6 weeks in the Rapid Release Cycle and makes it such the recommended Mozilla Enterprise Browser version.
You can download FF 24 ESR here: http://www.mozilla.org/en-US/firefox/organizations/all.html
Mozilla Firefox 24 ESR has been successfully tested with NetWeaver version 7.0 and later.
As usual, for further details and SAP restrictions see:
- SAP Product Availability Matrix (PAM): http://service.sap.com/pam
- Firefox browser note: https://service.sap.com/sap/support/notes/990034