Read this news:
http://lists.grok.org.uk/pipermail/full-disclosure/2007-December/058839.html
Or
http://seclists.org/fulldisclosure/2007/Dec/0103.html
Any information from Nokia?
Nokia N95 cellphone remote DoS using the SIP Stack
well, thats v12... so if your that concerned about it... you could update to v20.. 😉
Other than that... keep your eyes peeled