Software development companies are increasingly concerned about their impact on the environment. This is translated into the incorporation of actions related to software sustainability in their Corporate Social Responsibility (CSR) document. CSR reflects a company's obligations to society and the environment. However, we have found that companies do not always have the necessary knowledge to be able to include actions related to software sustainability. Moreover, there is still a lot of work to be done, as the number of actions they incorporate is often insufficient. Taking all this into account, we consider it essential for software development companies to have a tool that allows them to assess their level of software sustainability, based on the actions of their CSR, and to automatically provide them with a series of improvements to advance their level of software sustainability. Therefore, this paper introduces CSRE4SOC, a tool for the evaluation and monitoring of the software sustainability level of software development companies according to their CSR.