Is this the correct patch for CiviCRM version 4.6 here CIVI-SA-2016-23?
Specific answer on patching CRM-19709 for 4.6.10


Go to the appropriate Github repo, civicrm-core
Select the branch you want to find a backported patch for, 4.6
Read the commit messages and find commit(s) you want to apply, 3a7376 and 675201
Append .patch to those commit URLs: 3a7376.patch, 675201.patch
Try a patch --dry-run dry-run to see if the patches apply, in the order they were applied to the 4.6 branch.
If that works (no errors), apply the patches by dropping the --dry-run option.


To perform the actual patch, I tend to use curl PATCHURL(S) | patch -p1, so the command I'd use to test if the patches will apply will be:

curl \
  https://github.com/civicrm/civicrm-core/commit/67520196442e493ea1c6ddfcd4954d0f3c7ab3fe.patch \
  https://github.com/civicrm/civicrm-core/commit/3a73760d967edab137fe8eae20fdf63967be9ecf.patch \
| patch -p1 --dry-run


Pulling patches directly from a URL saves a few steps, and means we don't end up with abcdef.patch left on disk after.

Please see also my separate answer on how to avoid getting into this situation :)