Hi, these older units and many of the new ones today use what is called a compression fitting where the gas supply lines meet the burners. With time these can become loose or in your case deteriorate and cause small gas leaks that will ignite where they are not supposed too! This can be repaired but I will warn you now most service shops will not want to deal with it due to liability issues and the fact most of the lines will have to be custom made because factory lines and fittings are not going to be available any longer.
Home Appliance Technician
19 years in the appliance service industry. I can answer any question you may have with any brand.