Unspecified vulnerability in the network bridge functionality on the Apple Time Capsule, AirPort Extreme Base Station, and AirPort Express Base Station with firmware before 7.5.2 allows remote attackers to cause a denial of service (networking outage) via a crafted DHCP reply.
http://www.securitytracker.com/id?1024907
http://support.apple.com/kb/HT4298
http://lists.apple.com/archives/security-announce/2010//Dec/msg00001.html