On Running Disabled Networking Features: A Taxonomy with Security Implications

Abstract

The attack surface of a networking system is related to the number of features it supports. To reduce attack surface of the system, an important step is to disable unused features. Generally, this practice is considered sufficient to tackle the security implications of the unused features. This paper argues that this practice is necessary but not sufficient. To support this thesis, a taxonomy is provided which illustrates various ways in which a seemingly disabled feature may get a chance to run.