mumble-voip/mumble — pull request #173 by tipabu (2013-09-12 20:57:08+00:00)
Title: When write access is disabled and read access is restricted, clients can connect with an empty secret.

If a server is configured like:

icesecretread=asdf
icesecretwrite=

(ie, read access is restricted, and write access is disabled), then clients can still connect by passing an empty password.