TLD Survey: Risks
Open Recursive/Caching Server, Cons
- Anyone can abuse your server
- Including using your server to DoS another
- Including having your server effectively host their domain
- Leaves you much more vulnerable to cache poisoning/pollution
- If you are also authoritative, you risk passing on poison/pollution to unsuspecting external clients
- Hostname-based security can be easily by-passed
- Poisoned/polluted parent zone increases security risk for all children
- Eugene Kashpureff used this attack in 1997
- Causes one server (or set of servers) to do much more work than would otherwise be necessary