In Eclipse ThreadX NetX Duo versions 6.0 through 6.5.2.202603a, the NetX Secure DTLS server allocates a session from its fixed session pool for the first datagram from any unrecognised address and port, before the cookie exchange, and never releases a session whose handshake stalls. A remote, unauthenticated attacker can exhaust the pool with one spoofed datagram per source and deny DTLS service to legitimate clients until the application resets the sessions.
CWE-770, CWE-772