Ahmed Zerouali

Ahmed Zerouali, Tom Mens, Alexandre Decan et al.

The increasing interest in open source software has led to the emergence of large language-specific package distributions of reusable software libraries, such as npm and RubyGems. These software packages can be subject to vulnerabilities that may expose dependent packages through explicitly declared dependencies. Using Snyk's vulnerability database, this article empirically studies vulnerabilities affecting npm and RubyGems packages. We analyse how and when these vulnerabilities are disclosed and fixed, and how their prevalence changes over time. We also analyse how vulnerable packages expose their direct and indirect dependents to vulnerabilities. We distinguish between two types of dependents: packages distributed via the package manager, and external GitHub projects depending on npm packages. We observe that the number of vulnerabilities in npm is increasing and being disclosed faster than vulnerabilities in RubyGems. For both package distributions, the time required to disclose vulnerabilities is increasing over time. Vulnerabilities in npm packages affect a median of 30 package releases, while this is 59 releases in RubyGems packages. A large proportion of external GitHub projects is exposed to vulnerabilities coming from direct or indirect dependencies. 33% and 40% of dependency vulnerabilities to which projects and packages are exposed, respectively, have their fixes in more recent releases within the same major release range of the used dependency. Our findings reveal that more effort is needed to better secure open source package distributions.

Ahmed Zerouali, Tom Mens, Gregorio Robles et al.

Software systems often leverage on open source software libraries to reuse functionalities. Such libraries are readily available through software package managers like npm for JavaScript. Due to the huge amount of packages available in such package distributions, developers often decide to rely on or contribute to a software package based on its popularity. Moreover, it is a common practice for researchers to depend on popularity metrics for data sampling and choosing the right candidates for their studies. However, the meaning of popularity is relative and can be defined and measured in a diversity of ways, that might produce different outcomes even when considered for the same studies. In this paper, we show evidence of how different is the meaning of popularity in software engineering research. Moreover, we empirically analyse the relationship between different software popularity measures. As a case study, for a large dataset of 175k npm packages, we computed and extracted 9 different popularity metrics from three open source tracking systems: libraries.io, npmjs.com and GitHub. We found that indeed popularity can be measured with different unrelated metrics, each metric can be defined within a specific context. This indicates a need for a generic framework that would use a portfolio of popularity metrics drawing from different concepts.

Ahmed Zerouali, Tom Mens, Gregorio Robles et al.

Packaging software into containers is becoming a common practice when deploying services in cloud and other environments. Docker images are one of the most popular container technologies for building and deploying containers. A container image usually includes a collection of software packages, that can have bugs and security vulnerabilities that affect the container health. Our goal is to support container deployers by analysing the relation between outdated containers and vulnerable and buggy packages installed in them. We use the concept of technical lag of a container as the difference between a given container and the most up-to-date container that is possible with the most recent releases of the same collection of packages. For 7,380 official and community Docker images that are based on the Debian Linux distribution, we identify which software packages are installed in them and measure their technical lag in terms of version updates, security vulnerabilities and bugs. We have found, among others, that no release is devoid of vulnerabilities, so deployers cannot avoid vulnerabilities even if they deploy the most recent packages. We offer some lessons learned for container developers in regard to the strategies they can follow to minimize the number of vulnerabilities. We argue that Docker container scan and security management tools should improve their platforms by adding data about other kinds of bugs and include the measurement of technical lag to offer deployers information of when to update.