Problem Description:
libalias(3) packet handlers do not properly validate the packet length before
accessing the protocol headers. As a result, if a libalias(3) module does
not properly validate the packet length before accessing the protocol header,
it is possible for an out of bound read or write condition to occur.
Impact:
A malicious attacker could send specially constructed packets that exploit
the lack of validation allowing the attacker to read or write memory either
from the kernel (for the in-kernel NAT implementation) or from the process
space for natd (for the userspace implementation).