In a ubiquitous environment, the hardware resources are limited; thus, an appropriate resource management mechanism is required for guaranteeing its processing activity. However, most operating systems (OSs) lack an access control mechanism for CPU resources to guarantee satisfactory processing and to safeguard the system from malicious attacks that affect the CPU resources, resulting in denial of service (DoS). Access control is not intended for general OSs and CPU resources, which are important for the execution of a program. As a result, OSs cannot control the usage ratio of CPU resources. In this paper, we propose an access control model for CPU resources based on an execution resource. The proposed model can control the usage ratio of CPU resources appropriately for each program domain. This execution resource can be applied to mitigate DoS attacks.