Security vulnerabilities are defects that enable an external party to compromise a system. Our research indicates that improving software quality by reducing the number of errors also reduces the number of vulnerabilities and hence improves software security. Some portion of security vulnerabilities (maybe over half of them) are also quality defects. Can quality defect models that predict quality results be applied to security to predict security results? Simple defect models focus on an enumeration of development errors after they have occurred and do not relate directly to operational security vulnerabilities, except when the cause is quality related. In this podcast, Carol Woody and Bill Nichols discuss how a combination of software development and quality techniques can improve software security.