bind-dyndb-ldap: denial of service

A denial of service flaw was found in the way the bind-dyndb-ldap, a dynamic LDAP back-end plug-in for BIND providing LDAP database back-end capabilities, performed LDAP connection errors handling / attempted to recover, when an error during a LDAP search happened for a particular DNS query. When the Berkeley Internet Name Domain (BIND) server was patched to support dynamic loading of database back-ends, and the LDAP database back-end was enabled, a remote attacker could use this flaw to cause denial of service (named process hang) via DNS query for zone served by bind-dyndb-ldap.