  Self-Admitted Technical Debt (SATD) encompasses a wide array of sub-optimal
design and implementation choices reported in software artefacts (e.g., code
comments and commit messages) by developers themselves. Such reports have been
central to the study of software maintenance and evolution over the last
decades. However, they can also be deemed as dreadful sources of information on
potentially exploitable vulnerabilities and security flaws. This work
investigates the security implications of SATD from a technical and
developer-centred perspective. On the one hand, it analyses whether security
pointers disclosed inside SATD sources can be used to characterise
vulnerabilities in Open-Source Software (OSS) projects and repositories. On the
other hand, it delves into developers' perspectives regarding the motivations
behind this practice, its prevalence, and its potential negative consequences.
We followed a mixed-methods approach consisting of (i) the analysis of a
preexisting dataset containing 8,812 SATD instances and (ii) an online survey
with 222 OSS practitioners. We gathered 201 SATD instances through the dataset
analysis and mapped them to different Common Weakness Enumeration (CWE)
identifiers. Overall, 25 different types of CWEs were spotted across commit
messages, pull requests, code comments, and issue sections, from which 8 appear
among MITRE's Top-25 most dangerous ones. The survey shows that software
practitioners often place security pointers across SATD artefacts to promote a
security culture among their peers and help them spot flaky code sections,
among other motives. However, they also consider such a practice risky as it
may facilitate vulnerability exploits. Our findings suggest that preserving the
contextual integrity of security pointers disseminated across SATD artefacts is
critical to safeguard both commercial and OSS solutions against zero-day
attacks.
