Information disclosure via offset-blind PSK bounds check

Buffer over-read in Eclipse ThreadX NetX Duo before 6.4.4 allows remote attackers to read two bytes beyond a TLS extension buffer. The _nx_secure_tls_process_clienthello_psk_extension() function compares the PSK identity-list length with the full extension length after advancing its offset by two bytes, letting a crafted ClientHello drive the parser past the buffer. Exploitation requires a reachable NetX Secure TLS endpoint that processes the crafted PSK extension; the published impact is limited to low-sensitivity information disclosure.