The Popularity Hypothesis in Software Security: A Large-Scale Replication with PHP Packages

There has been a long-standing hypothesis that a software's popularity is related to its security or insecurity in both research and popular discourse. There are also a few empirical studies that have examined the hypothesis, either explicitly or implicitly. The present work continues with and contributes to this research with a replication-motivated large-scale analysis of software written in the PHP programming language. Two datasets are used: the first contains nearly four hundred thousand open source software packages written in PHP and the second addresses over six thousand WordPress components. According to the results based on vulnerabilities reported, the hypothesis holds: packages having seen reported vulnerabilities over their release histories are generally more popular than packages for which fewer or no vulnerabilities have been reported. With this replication results, the paper contributes to the efforts to strengthen the empirical knowledge basis in cyber and software security. In addition, the paper makes a contribution to the recent discussion on the terminology about software vulnerabilities and the associated construct validity problems that follow.