In Eclipse Californium version 2.0.0 to 2.7.2 and 3.0.0-3.5.0 a DTLS resumption handshake falls back to a DTLS full handshake on a parameter mismatch without using a HelloVerifyRequest. Especially, if used with certificate based cipher suites, that results in message amplification (DDoS other peers) and high CPU load (DoS own peer). The misbehavior occurs only with DTLS_VERIFY_PEERS_ON_RESUMPTION_THRESHOLD values larger than 0.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Californium | Eclipse | 2.0.0 (including) | 2.7.2 (including) |
| Californium | Eclipse | 3.0.0 (including) | 3.5.0 (including) |