http://www.heise.de/newsticker/meldung/ ... 97287.html (German)
They say, the fault lies in the verification of the offered SSL certificates, which makes it rather easy to link up into the encrypted data transfer. They could record login data or decrypt HTTPS websites that were loaded with the TV's browser. They strongly advise against using the TV browser for online banking or other confidential data.
Apparently Samsung is going to fix this in a new firmware, but there is no release date.