The Service Layer in SAP Business One, allows attackers to potentially gain unauthorized access and impersonate other users in the application to perform unauthorized actions. Due to the improper session management, the attackers can elevate themselves to higher privilege and can read, modify and/or write new data. To gain authenticated sessions of other users, the attacker must invest considerable time and effort. This vulnerability has a high impact on the confidentiality and integrity of the application with no effect on the availability of the application.