In the short run, an economy-wide negative supply shock will shift the aggregate supply curve leftward, decreasing the output and increasing the price level.
[1] For example, the imposition of an embargo on trade in oil would cause an adverse supply shock, since oil is a key factor of production for a wide variety of goods.
A supply shock can cause stagflation due to a combination of rising prices and falling output.
The 1973 Oil Crisis is often used as the exemplar case of a supply shock, when OPEC restrictions on production and sale of petroleum resulted in fuel shortages throughout the developed world.
In the short run, an economy-wide positive supply shock will shift the aggregate supply curve rightward, increasing output and decreasing the price level.