The _udp_lib_get_port function in net/ipv4/udp.c in Linux kernel 2.6.21 and earlier does not prevent a bind to a port with a local address …

The _udp_lib_get_port function in net/ipv4/udp.c in Linux kernel 2.6.21 and earlier does not prevent a bind to a port with a local address when there is already a bind to that port with a wildcard local address, which might allow local users to intercept local traffic for daemons or other applications.