In Eclipse ThreadX NetX Duo versions 6.0 through 6.5.2.202603a, the NetX Secure TLS client's ServerHello parser and DTLS client's HelloVerifyRequest parser read fields before checking that the message is long enough to contain them. A malicious server or an on-path attacker can make the client read up to three bytes past a handshake message, which can fault the client on targets with memory protection.

Two client-side TLS/DTLS handshake parsers in NetX Secure read fields from a server-supplied message before validating that the message is long enough to contain them. Both are bounded out-of-bounds reads on a remotely reachable path, both are reached from a TLS or DTLS client connecting to a malicious or malformed server, and both have the same shape: the bounds check exists and returns the correct status, but it runs after the read it is meant to guard.