Wine bottles with corks should be stored on their side as there is a danger that the cork could dry out and let air in that could ruin the wine. Screw tops are OK upright. Cabernet's should be fine for 20 years or more. Not all of them will continue to improve for that length of time though
As Milvus says the Cabernet should be fine as long as the cork hasn't dried out too much. You may need to decant it first though. Check if there's any sediment in the bottom. The semillon will probably be OK too but past its best.
The best way to find out is to open them! Cheers!