Integer overflow in the netsnmp_create_subtree_cache function in agent/snmp_agent.c in net-snmp 5.4 before 5.4.2.1, 5.3 before 5.3.2.3, and 5.2 before 5.2.5.1 allows remote attackers to cause a denial of service (crash) via a crafted SNMP GETBULK request, which triggers a heap-based buffer overflow,  related to the number of responses or repeats.