FreeBSD Security Advisory (FreeBSD-SA-03:14.arp.asc)

The remote host is missing an update to the system as announced in the referenced advisory FreeBSD-SA-03:14.arp.asc

The Address Resolution Protocol (ARP) is fundamental to the operation of IP with a variety of network technologies, such as Ethernet and WLAN. It is used to map IP addresses to MAC addresses, which enables hosts on a local network segment to communicate with each other directly. These mappings are stored in the system's ARP cache. FreeBSD's ARP cache is implemented within the kernel routing table as a set of routes for the address family in use that have the LLINFO flag set. This is most commonly often AF_INET (for IPv4). Normally, when a FreeBSD system receives an ARP request for a network address configured on one of its interfaces from a system on a local network, it adds a reciprocal ARP entry to the cache for the system from where the request originated. Expiry timers are used to purge unused entries from the ARP cache. A reference count is maintained for each ARP entry. If the reciprocal ARP entry is not in use by an upper layer protocol, the reference count will be zero. Under certain circumstances, it is possible for an attacker to flood a FreeBSD system with spoofed ARP requests, causing resource starvation which eventually results in a system panic. (The critical condition is that a route exists for the apparent source of the ARP request. This is always the case if the system has a default route configured for that protocol family.) If a large number of ARP requests with different network protocol addresses are sent in a small space of time, resource starvation can result, as the arplookup() function does not delete unnecessary ARP entries cached as the result of responding to an ARP request. NOTE WELL: Other BSD-derived systems may also be affected, as the affected code dates well back to the CSRG branches.

Upgrade your system to the appropriate stable release or security branch dated after the correction date https://secure1.securityspace.com/smysecure/catid.html?in=FreeBSD-SA-03:14.arp.asc