The zbx_get_next_field function in libs/zbxcommon/str.c in Zabbix Server before 1.6.8 allows remote attackers to cause a denial of service (crash) via a request that lacks expected separators, which triggers a NULL pointer dereference, as demonstrated using the Command keyword.
Improper Restriction of Operations within the Bounds of a Memory Buffer The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.