Missing HelloVerifyRequest cookie validation in the NetX Secure DTLS server

In Eclipse ThreadX NetX Duo versions 6.0 through 6.5.2.202603, the NetX Secure DTLS server never compares the cookie a client returns with the one it issued, and treats any non-empty cookie as verified. A remote attacker can make the server send its full handshake flight, several kilobytes, to a forged source address, using it to reflect amplified traffic at a third party.

Out-of-bounds read via an empty signature BIT STRING in NetX Secure X.509 parsing

In Eclipse ThreadX NetX Duo versions up to and including 6.5.2.202603, the NetX Secure X.509 parser accepts a certificate whose signature is an empty BIT STRING and records a signature length of 0xFFFFFFFF. A remote peer can present such a certificate during the TLS handshake, before authentication, and make the device read far outside the certificate buffer during signature verification, which is expected to fault.

Out-of-bounds read in the NetX Duo SNMP OID parser via a multi-byte BER length

In Eclipse ThreadX NetX Duo versions up to and including 6.5.2.202603, the SNMP agent's OID parser uses a multi-byte BER length from the request without checking it against the bytes present, and reads past the end of the packet buffer. A remote, unauthenticated attacker can send a crafted SNMP request that makes the agent read adjacent memory into its OID state, faulting the agent on targets with memory protection.

ICMPv6 option validation accepts a trailing byte residue, sending the Router Advertisement, Neighbor Solicitation, Neighbor Advertisement and Redirect option walkers past the packet or into a permanent loop

In Eclipse ThreadX NetX Duo versions up to and including 6.5.2.202603, built with IPv6, the ICMPv6 option validator accepts an option area that ends in a one- or two-byte residue, and the Router Advertisement, Neighbor Solicitation, Neighbor Advertisement and Redirect handlers then walk it without length checks. A host on the local link can send one such message to make the IP thread read past the packet or loop forever, and can place off-packet memory in the neighbor cache.

Unbounded DATA datagram in the NetX Duo TFTP server causes an out-of-bounds read and a permanent stall

In Eclipse ThreadX NetX Duo versions up to and including 6.5.2.202603, built with packet chaining, the TFTP server does not bound the length of a received DATA datagram. An unauthenticated peer can upload an oversized datagram that writes memory beyond the received packet into the file and read it back by downloading the file, and the same datagram can suspend the server thread permanently.

Out-of-bounds read in the NetX Secure DTLS ClientHello parser

In Eclipse ThreadX NetX Duo versions up to and including 6.5.2.202603, built with DTLS server support, the NetX Secure DTLS server's ClientHello parser reads the session ID, cookie and ciphersuite list without bounding them by the bytes remaining in the message. An unauthenticated peer can send a ClientHello declaring fields longer than the message and make the server read past it; nothing read is sent back to the peer, and the read can fault the server only on targets that trap the address beyond the buffer.

Out-of-bounds reads in NetX Secure client-side handshake parsing (ServerHello and HelloVerifyRequest)

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.

FTP Passive Data Connection Not Bound to the Authenticated Control Peer

In Eclipse ThreadX NetX Duo versions 6.0 through 6.5.2.202603a, the FTP server accepts the first connection to a passive data port without checking that it comes from the client that requested passive mode. An unauthenticated network attacker who connects to the predictable port first receives the file an authenticated user downloads, or supplies the content of the file the user uploads.

Unbounded PPP IPCP Option Parsing Causes a Worker Stall and Out-of-bounds Read

In Eclipse ThreadX NetX Duo versions 6.0 through 6.5.2.202603a, the PPP IPCP code parses a peer's Configure-Nak without validating each option's length. A malicious PPP peer can stall the PPP thread indefinitely with a zero-length option, taking the link down, and can read back up to four bytes of packet-buffer memory per exchange with a short address option.

Out-of-bounds Read from Unvalidated MSRP Attribute List Length

In Eclipse ThreadX NetX Duo versions 6.4.0 through 6.5.2.202603a, built with VLAN and SRP support, the MSRP parser uses the attribute list length from the received frame without comparing it with the packet length. An unauthenticated station on the same Layer 2 segment can send a short MSRP frame declaring a long list and make the MRP worker read far past the received packet, faulting it on targets with memory protection.

NULL pointer dereference when evicting the last MSRP attribute in a participant's list

In Eclipse ThreadX NetX Duo versions 6.4.0 through 6.5.2.202603a, built with VLAN and SRP support, evicting the last attribute in an MRP participant's list writes through a null successor pointer. An unauthenticated station on the same Layer 2 segment can fault the MRP worker thread by declaring one MSRP attribute and withdrawing it, and ordinary withdrawals by legitimate stations reach the same path.

NULL Pointer Dereference on MSRP Attribute Table Exhaustion

In Eclipse ThreadX NetX Duo versions 6.4.0 through 6.5.2.202603a, built with VLAN and SRP support, the MSRP attribute lookup writes through the null pointer returned by its allocator when the ten-entry attribute table is full. An unauthenticated station on the same Layer 2 segment can fault the MRP worker thread by declaring enough new attributes, and Talker Failed declarations hold table entries that are never released.

The FTP client trusts arbitrary IP addresses in the PASV server response

In Eclipse ThreadX NetX Duo versions 6.0 through 6.5.2.202603a, the FTP client in IPv4 passive mode opens its data connection to whatever address the server names in its 227 reply instead of the server it is talking to. A malicious FTP server can make the client connect to any host and port the device can reach, using it to scan the internal network and to deliver uploads to internal services.

TFTP client and server copy the ERROR packet message without bounding the read against the packet

In Eclipse ThreadX NetX Duo versions 6.0 through 6.5.2.202603a, the TFTP client copies the message of a received ERROR packet without bounding the copy by the end of the datagram, and the TFTP server reads one byte past a minimal ERROR packet. A malicious TFTP server can make the client copy up to 64 bytes of adjacent packet-pool memory into the error string the application retrieves, or fault on targets with memory protection.

When a TLS 1.3 client processes a HelloRetryRequest, it copies the server's cookie into its second ClientHello without checking that the cookie fits in the outgoing packet. Both the length and the contents of that cookie come from the peer, and the write happens before certificate authentication completes, so a malicious or compromised server can overwrite memory past the caller supplied TLS packet buffer without presenting a certificate. Only the client path is affected.

NetX Duo MQTT Client Denial of Service via Malformed PUBLISH Message

The NetX Duo MQTT client leaks the packet carrying a malformed PUBLISH message. Each malformed PUBLISH costs one packet, or one chain of packets, from the network driver's receive pool, and nothing returns it. A peer that can deliver a few dozen such messages exhausts the pool and stops all inbound network traffic on the device until it is rebooted.

NetX Duo WebSocket Client Buffer Overwrite via Masking Key

NetX Duo's WebSocket client resets the unmasking cursor to the first `NX_PACKET` each time it advances through a chained packet, while the loop's upper bound belongs to the current packet. With the standard contiguous packet-pool layout, a masked server frame split across two packets therefore drives the XOR loop through the first packet's unused payload area and on through the second packet's `NX_PACKET` control block. The four-byte WebSocket masking key controls the bytes written, so the corruption is attacker-chosen rather than incidental.

The `_nx_secure_x509_asn1_tlv_block_parse()` function parses ASN.1 TLV (tag-length-value) blocks out of DER-encoded data. It is the primitive underneath all X.509 certificate parsing in NetX Secure, and therefore runs on certificates supplied by a remote peer during the TLS handshake. The function reads the one-byte ASN.1 tag from the caller's buffer *before* checking that the buffer holds at least one byte. When a caller passes a remaining length of zero, the guard correctly returns `NX_SECURE_X509_ASN1_LENGTH_TOO_LONG`, but the read has already happened one byte past the end of the buffer. code: nx_secure/src/nx_secure_x509_asn1_tlv_block_parse.c ``` UINT _nx_secure_x509_asn1_tlv_block_parse(const UCHAR *buffer, ULONG *buffer_length, USHORT *tlv_type, USHORT *tlv_tag_class, ULONG *tlv_length, const UCHAR **tlv_data, ULONG *header_length) { UINT current_index; USHORT current_tag; ULONG length; ULONG length_bytes; current_index = 0; current_tag = buffer[current_index]; /* <-- read before the bounds check */ if (*buffer_length < 1) { return(NX_SECURE_X509_ASN1_LENGTH_TOO_LONG); } ``` The remainder of the function is correctly ordered. The multi-byte length path is guarded by `length_bytes > 4 || length_bytes > *buffer_length` before its read loop, the decoded value is checked against `length > *buffer_length`, and the second single-byte length read follows its own `*buffer_length < 1` guard. The tag read is the only load placed ahead of its check.

NetX Duo TLS MAC Verification Bypass via Empty Application-Data Record

NetX Secure TLS accepts an empty application-data record without verifying its message authentication code. In `_nx_secure_verify_mac`, a decrypted application record whose length equals the negotiated MAC size is treated as valid and returns success after advancing the receive sequence number. The received MAC is never generated or compared. Empty TLS application-data records are legal, and are commonly emitted by TLS 1.0 implementations as a BEAST mitigation.

When NetX Secure is built with `NX_SECURE_KEY_CLEAR`, every TLS record sent on an active session is wiped after it has been handed to TCP. By then the TCP layer owns the packet chain and may already have released it to the packet pool. The wipe therefore writes zeros into packets that are free or in use by another thread, and when a reused packet's pointers no longer describe the old data, the length of the wipe underflows and it runs past the end of the packet pool.