net-snmp: A buffer overflow in the handling of the INDEX of NET-SNMP-VACM-MIB can cause an out-of-bounds memory access.

net-snmp provides various tools relating to the Simple Network Management Protocol. Prior to version 5.9.2, a buffer overflow in the handling of the `INDEX` of `NET-SNMP-VACM-MIB` can cause an out-of-bounds memory access. A user with read-only credentials can exploit the issue. Version 5.9.2 contains a patch. Users should use strong SNMPv3 credentials and avoid sharing the credentials. Those who must use SNMPv1 or SNMPv2c should use a complex community string and enhance the protection by restricting access to a given IP address range.