Contiki-NG vulnerabilities

Contiki-NG's MQTT client in parse_publish_vhdr() in os/net/app-layer/mqtt/mqtt.c sets topic_len_received=1 before checking topic_len against the 64-byte limit, so an over-length topic returns early but leaves the flag set. On the next TCP segment, the parser skips the length-reading block and performs a memcpy with an unvalidated length, leading to overflow of the topic[] buffer and overwriting adjacent fields, including the payload_chunk pointer. This can enable remote code execution on devices without memory protection.

Contiki-NG's DNS/mDNS resolver in skip_name() in os/services/resolv/resolv.c walks DNS wire-format name labels with no packet-boundary check, and the caller in newdata() iterates nquestions times from the attacker-controlled DNS header before validating the transaction ID. An attacker can set nquestions higher than the number of complete questions, causing out-of-bounds reads past the UDP packet buffer and disclosing memory contents or crashing the resolver.

Contiki-NG's LwM2M TLV parser in lwm2m_tlv_read() in os/services/lwm2m/lwm2m-tlv.c ignores its caller-supplied buffer length argument and reads up to six bytes from the input buffer with no bounds check. A crafted CoAP WRITE with a final TLV supplying exactly one byte triggers up to five out-of-bounds reads of heap memory, disclosing memory contents (including key material and peer addresses) through the parsed tlv->id, tlv->length, and tlv->value fields. In LwM2M NoSec mode, the default for constrained devices, no authentication is required.

Contiki-NG is an operating system for IoT devices. In version 4.8 and prior, when processing ICMP DAO packets in the `dao_input_storing` function, the system does not verify that the packet buffer is large enough, which can lead to out-of-bounds reads.

Contiki-NG, an operating system for IoT devices, has a vulnerability that allows reading data out of bounds of the IPv6 buffer when processing the MSS option in TCP packets. The issue involves buffer indexing in the module os/net/ipv6/uip6.c, which may lead to unauthorized memory access.