Can a judgment be assessed on an individual with no income other than social security and only asset is his home?

Yes. A judgment can be entered against a defendant but whether or not it can be enforced is another matter. Defendants of civil suits are allowed to protect a certain amount of personal (clothing, household goods, investments, etc.) and real property (houses, land, etc.). Social Security benefits of all types are exempt from creditor action. The judgment creditor can in most instances place a lien against any real property held by the judgment debtor. The laws of the debtor's state and the way the property is titled determines what if any action a judgment creditor can take against a home.