This article is about a security risk that I found while using Skype and Vodafone voicemail. In this article I will dive into a specific situation concerning the security of one’s Vodafone voicemail (Netherlands) in combination with Skype‘s ability to spoof the caller ID. Besides that I look at the main concern: trusting a caller ID for authentication purposes.

Since June 2005, I’ve been collecting tracklog data using my (then) Garmin GPS 60 (CSx). This means that every time I go cycle racing, walking, sailing, ice skating or even flying, I bring my Garmin, turn it on and (automatically) log the track.