An issue was discovered in Contiki through 3.0. An Integer Overflow exists in the uIP TCP/IP Stack component when parsing TCP MSS options of IPv4 network packets in uip_process in net/ipv4/uip.c.

Buffer overflows were discovered in Contiki-NG 4.4 through 4.5, in the SNMP agent. The function parsing the received SNMP request does not verify the input message's requested variables against the capacity of the internal SNMP engine buffer. If the number of variables in the request exceeds the allocated buffer, a memory write out of the buffer boundaries occurs. This write operation provides a possibility to overwrite other variables allocated in the .bss section by the application. Because the sender of the frame is in control of the content that will be written beyond the buffer limits, and there is no strict process memory separation, this issue may allow overwriting of sensitive memory areas of an IoT device.

Buffer overflows were discovered in Contiki-NG 4.4 through 4.5, in the SNMP bulk get request response encoding function. The function parsing the received SNMP request does not verify the input message's requested variables against the capacity of the internal SNMP engine buffer. When a bulk get request response is assembled, a stack buffer dedicated for OIDs (with a limited capacity) is allocated in snmp_engine_get_bulk(). When snmp_engine_get_bulk() is populating the stack buffer, an overflow condition may occur due to lack of input length validation. This makes it possible to overwrite stack regions beyond the allocated buffer, including the return address from the function. As a result, the code execution path may be redirected to an address provided in the SNMP bulk get payload. If the target architecture uses common addressing space for program and data memory, it may also be possible to supply code in the SNMP request payload, and redirect the execution path to the remotely inj…

Buffer overflows were discovered in Contiki-NG 4.4 through 4.5, in the SNMP agent. Functions parsing the OIDs in SNMP requests lack sufficient allocated target-buffer capacity verification when writing parsed OID values. The function snmp_oid_decode_oid() may overwrite memory areas beyond the provided target buffer, when called from snmp_message_decode() upon an SNMP request reception. Because the content of the write operations is externally provided in the SNMP requests, it enables a remote overwrite of an IoT device's memory regions beyond the allocated buffer. This overflow may allow remote overwrite of stack and statically allocated variables memory regions by sending a crafted SNMP request.

Memory access out of buffer boundaries issues was discovered in Contiki-NG 4.4 through 4.5, in the SNMP BER encoder/decoder. The length of provided input/output buffers is insufficiently verified during the encoding and decoding of data. This may lead to out-of-bounds buffer read or write access in BER decoding and encoding functions.

An issue was discovered in Contiki-NG through 4.3 and Contiki through 3.0. A buffer overflow is present due to an integer underflow during 6LoWPAN fragment processing in the face of truncated fragments in os/net/ipv6/sicslowpan.c. This results in accesses of unmapped memory, crashing the application. An attacker can cause a denial-of-service via a crafted 6LoWPAN frame.

An issue was discovered in Contiki-NG through 4.3 and Contiki through 3.0. An out of bounds write is present in the data section during 6LoWPAN fragment re-assembly in the face of forged fragment offsets in os/net/ipv6/sicslowpan.c.

Contiki-NG before 4.2 has a stack-based buffer overflow in the push function in os/lib/json/jsonparse.c that allows an out-of-bounds write of an '{' or '[' character.

An issue was discovered in the MQTT server in Contiki-NG before 4.2. The function parse_publish_vhdr() that parses MQTT PUBLISH messages with a variable length header uses memcpy to input data into a fixed size buffer. The allocated buffer can fit only MQTT_MAX_TOPIC_LENGTH (default 64) bytes, and a length check is missing. This could lead to Remote Code Execution via a stack-smashing attack (overwriting the function return address). Contiki-NG does not separate the MQTT server from other servers and the OS modules, so access to all memory regions is possible.

contiki-ng version 4 contains a Buffer Overflow vulnerability in AQL (Antelope Query Language) database engine that can result in Attacker can perform Remote Code Execution on device using Contiki-NG operating system. This attack appear to be exploitable via Attacker must be able to run malicious AQL code (e.g. via SQL-like Injection attack).