Disaster Survivors Fairness Act of 2023 This bill makes changes in the process for seeking and providing assistance following a major disaster. Specifically, the bill directs the Federal Emergency Management Agency (FEMA) to establish and maintain a web-based interagency electronic information sharing system, to be known as the unified disaster application system, to facilitate the administration of a universal application for direct federal disaster assistance. The President may provide (1) assistance to respond to the disaster-related housing needs of individuals and households who are displaced from their predisaster primary residence that is damaged by a major disaster (currently, such residences must be rendered uninhabitable); and (2) direct assistance for repairs and for cost-effective hazard mitigation measures that reduce threats to life and property or future damage. FEMA may (1) provide funding to a state agency to establish, update, or operate a website to provide information relating to postdisaster recovery funding and resources; and (2) reimburse a state, tribal, or local government for certain costs relating to sheltering emergency response personnel. The bill extends FEMA's authority to implement state-managed housing assistance as a pilot program. FEMA must conduct a study and develop a plan to address the challenges and disparities associated with providing housing assistance to survivors of major disasters or emergencies. The Government Accountability Office must report on (1) assistance issues, including improper and potentially fraudulent federal disaster assistance; and (2) the effectiveness, successes, and challenges of any state-managed housing assistance pilot program and make recommendations on how to improve the provision of assistance.