I experimented with the "Administration" and "Credentials" categories, along with the "Feeds" category, in the Edit Task UI.
All 3 categories exhibit the bug. If you check any box in the category and save the task, all of the permissions in that category are enabled.
It looks like within a category on the Edit Task UI, all of the input check boxes have the same name. e.g. All 8 check boxes in the Feeds category have the name "ah0~ah4~ah2~ah9".