Command authorization may be accomplished using the RADIUS protocol by providing a user profile on the server for each user. This user profile may be transferred to a network device, such as a NAS, when the user initiates a NAS session. It may be stored in a local cache and accessed each time the user attempts to execute a command. The user profile may contain a command set defined by regular expressions which can then be used to determine whether or not the command should be authorized. The command may then be authorized or rejected based on the results of this determination. After the session is completed, the user profile may be purged from the cache. The present invention allows for a dramatic savings in the traffic associated with command authorization and allows command authorization to be accomplished using the RADIUS protocol, which increases flexibility and NAS security.