If my Wild Magic Sorcerer rolled this, I would be thrilled
While this could be a burden if it was present all the time, I see this as being a handy tool for adventurers:
- Suddenly, they have a means to generate a very large amount of gold on demand. After this happens more than once, the table is probably going to want to use this to fund some of their more costly endeavors. Money is less game-breaking than it was in 3.5, but it does play a role.
- The character now has a very powerful attack option for 1d12 hours, which could be the entire thing and half the trip back if it occurs during a dungeon crawl. The bulk of the CR for a Medusa is coming from her petrifying gaze, which follows comparable rules with a DC14 and this DC is higher, and now a player character has that. For further comparison, the proposed effect occurs faster and more effectively than the 6th level spell, Flesh to Stone.
- The duration on the effect is extremely long when compared to other Wild Magic effects. In general, Wild Magic only has powerful, game changing effects (good or bad) over a short time period like Instantaneous or 1 Minute. Permanently turning yourself blue is a fun roleplay thing, but it generally doesn't impact combat unless you need to hide in a vat of blueberry pudding.
All in all, I think this curse is broken, but more in the sense that it's a very powerful tool more than a significant hindrance to a DnD adventuring party. Obviously, the pros/cons of the curse varies dramatically depending on the campaign, but I think most typical parties will turn this bane into a boon fairly quickly.
I would recommend following the guidance in the original table by shortening the duration, make the overall effect less controllable, base it upon something already within the game (this is off Flesh to Stone and the Medusa Gaze), and modify it such that it can do just as much good as it can do bad. In addition, I wouldn't set a DC for the save, just use the default which is the caster's DC. For example:
You are cursed with Midas Gaze. For the next minute, you automatically expend your Bonus Action to look at 1 random creature within 60 feet of you. If you shut your eyes, you are subject to the effect. That creature must succeed on a Constitution saving throw. If the saving throw fails by 5 or more, the creature is petrified as they instantly turn to gold. Otherwise, a creature that fails the save begins to turn to gold and is restrained. On a successful save, the creature isn't affected. A creature restrained by this effect must make another Constitution saving throw at the end of its turn becoming petrified and turning to gold on a failure or ending the effect on a success. A Remove Curse ends the effect.
This is more verbose than most Wild Magic effects, but I think it strikes a balance of potentially very powerful either for your team or against it, which is in line with a lot of the 'bad' effects.
Pro-tip: Don't use Wild Magic right next to your party.