Use of A Taxonomy of Security Faults

Security in computer systems is important so as to ensure reliable operation and to protect the integrity of stored information. Faults in the implementation of critical components can be exploited to breach security and penetrate a system. These faults must be identi ed, detected, and corrected to ensure reliability and safeguard against denial of service, unauthorized modi cation of data, or disclosure of information. We de ne a classi cation of security faults in the Unix operating system. We state the criteria used to categorize the faults and present examples of the di erent fault types. We present the design and implementation details of a prototype database to store vulnerability information collected from di erent sources. The data is organized according to our fault categories. The information in the database can be applied in static audit analysis of systems, intrusion detection, and fault detection. We also identify and describe software testing methods that should be e ective in detecting di erent faults in our classi cation scheme.