The dissector_postgresql function in dissectors/ec_postgresql.c in Ettercap before 0.8.1 allows remote attackers to cause a denial of service and possibly execute arbitrary code via a crafted password length, which triggers a 0 character to be written to an arbitrary memory location.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.