Denial of Service against AVM Fritz!Box 7050 (and others)

Discovered by: Matthias Wenzel
Advisory: http://mazzoo.de/blog/2007/01/18#FritzBox_DoS 

Manufacturer: AVM (www.avm.de) 
Product: Fritz!Box 750 (and others)

Vendor was notified 6 month ago (see blog entry by Matthias)

Sending a zero-length UDP packet to port 5060 (SIP) of a AVM Fritz!Box will
crash the VoIP-telephony application. This works from any IP-interface,
including the DSL line.


Collin (only delivering the message to FD and BugTraq)