An issue was discovered in Contiki-NG tinyDTLS through 2018-08-30. One incorrect handshake could complete with different epoch numbers in the packets Client_Hello, Client_key_exchange, and Change_cipher_spec, which may cause denial of service.
https://seclists.org/fulldisclosure/2024/Jan/14
https://github.com/contiki-ng/tinydtls/issues/27
http://packetstormsecurity.com/files/176625/Contiki-NG-tinyDTLS-Denial-Of-Service.html