Hi - we're using the SNOM phones in a privacy critical environment and also for some employees at home. This is realized by using a SRTP/TLS encryption to our own servers with our own CA.
The phones come with many more certificates pre-installed. Therefore we assume that the phone is intrinsically vulnerable to man-in-the-middle attacks, since likely every other by a pre-installed CA signed certificate will be accepted and trusted.
Therefore the question: How to remove or to disable the pre-installed certificates?