Answers: Somewhat, there are cold sores or hallucination blisters which are caused by the Herpes Simplex virus. These can go off anywhere in the mouth including on tight bound gum tissue. Then at hand are canker sores which are of unkown origin, also prearranged as apthous ulcers. These are not supposed to be cause by the herpes virus and the difference is these will never occur on the outside of the mouth, such as around the oral cavity, and will never occur on tightly bound gum tissue specifically on the palate of the mouth or close to the teeth.
They can be. But you can also get sores within your mouth from other things like braces, mild allergies to foods, etc... My dad get cankers when he eats walnuts.