Where do developers admit their security-related concerns?

Developers use different means to document the security concerns of their code. Because of all of these opportunities, they may forget where the information is stored, or others may not be aware of it, and leave it unmaintained for so long that it becomes obsolete, if not useless. In this work, we analyzed different sources of code documentation from four large-scale, real-world, open-source projects in an industrial setting to understand where developers report their security concerns. In particular, we manually inspected 2.559 instances taken from source code comments, commit messages, and issue trackers. Overall, we found that developers prefer to document security concerns in source code comments and issue trackers. We also found that the longer the comments stay unfixed, the more likely they remain unfixed. Thus, to create awareness among developers, we implemented a pipeline to remind them about the introduction or removal of comments pointing to a security problem.