Keeping with the Vancian theme of D&D’s magical system it makes sense that anyone who can decipher an arcane spell scroll should have a chance of casting it. This only affects arcane spells since divine spells are actually granted by divine powers. You follow the procedure as outlined in the DMG pg 200 with the following modifications:
If this is an arcane spell scroll, you must make an ability check using your Intelligence ability to determine whether you cast it successfully. The DC equals 10 + the spell’s level. On a failed check, the spell disappears from the scroll and you roll on the wild magic table to see if there are any side-effects replacing 99-00 with “no effect”.
The ability used is always Intelligence since arcane spells are essentially mathematical in nature and intelligence is the most applicable ability score.