Buffer Overflow vulnerability in coap_send function in libcoap library 4.3.1-103-g52cfd56 fixed in 4.3.1-120-ge242200 allows attackers to obtain sensitive information via malformed pdu.

libcoap 4.3.1 contains a buffer over-read via the function coap_parse_oscore_conf_mem at coap_oscore.c.

memory corruption in modem due to improper check while calculating size of serialized CoAP message

Information disclosure in modem due to improper input validation during parsing of upcoming CoAP message

Memory corruption in modem due to improper input validation while handling the incoming CoAP message

Memory correction in modem due to buffer overwrite during coap connection

In Eclipse Wakaama, ever since its inception until 2021-01-14, the CoAP parsing code does not properly sanitize network-received data.

Memory leaks were discovered in the CoAP library in Arm Mbed OS 5.15.3 when using the Arm mbed-coap library 5.1.5. The CoAP parser is responsible for parsing received CoAP packets. The function sn_coap_parser_options_parse() parses the CoAP option number field of all options present in the input packet. Each option number is calculated as a sum of the previous option number and a delta of the current option. The delta and the previous option number are expressed as unsigned 16-bit integers. Due to lack of overflow detection, it is possible to craft a packet that wraps the option number around and results in the same option number being processed again in a single packet. Certain options allocate memory by calling a memory allocation function. In the cases of COAP_OPTION_URI_QUERY, COAP_OPTION_URI_PATH, COAP_OPTION_LOCATION_QUERY, and COAP_OPTION_ETAG, there is no check on whether memory has already been allocated, which in conjunction with the option number integer overflow may lead to multiple assignments of allocated memory to a single pointer. This has been demonstrated to lead to memory leak by buffer orphaning. As a result, the memory is never freed.

A buffer over-read was discovered in the CoAP library in Arm Mbed OS 5.15.3. The CoAP parser is responsible for parsing received CoAP packets. The function sn_coap_parser_options_parse() parses the CoAP packet header starting from the message token. The length of the token in the received message is provided in the first byte parsed by the sn_coap_parser_options_parse() function. The length encoded in the message is not validated against the actual input buffer length before accessing the token. As a result, memory access outside of the intended boundary of the buffer may occur.

An infinite loop was discovered in the CoAP library in Arm Mbed OS 5.15.3. The CoAP parser is responsible for parsing received CoAP packets. The function sn_coap_parser_options_parse_multiple_options() parses CoAP options in a while loop. This loop's exit condition is computed using the previously allocated heap memory required for storing the result of parsing multiple options. If the input heap memory calculation results in zero bytes, the loop exit condition is never met and the loop is not terminated. As a result, the packet parsing function never exits, leading to resource consumption.

A buffer over-read was discovered in the CoAP library in Arm Mbed OS 5.15.3. The CoAP parser is responsible for parsing received CoAP packets. The function sn_coap_parser_options_parse_multiple_options() parses CoAP options that may occur multiple consecutive times in a single packet. While processing the options, packet_data_pptr is accessed after being incremented by option_len without a prior out-of-bounds memory check. The temp_parsed_uri_query_ptr is validated for a correct range, but the range valid for temp_parsed_uri_query_ptr is derived from the amount of allocated heap memory, not the actual input size. Therefore the check of temp_parsed_uri_query_ptr may be insufficient for safe access to the area pointed to by packet_data_pptr. As a result, access to a memory area outside of the intended boundary of the packet buffer is made.

Buffer over-reads were discovered in the CoAP library in Arm Mbed OS 5.15.3. The CoAP parser is responsible for parsing received CoAP packets. The function sn_coap_parser_options_parse() parses CoAP input linearly using a while loop. Once an option is parsed in a loop, the current point (*packet_data_pptr) is increased correspondingly. The pointer is restricted by the size of the received buffer, as well as by the option delta and option length bytes. The actual input packet length is not verified against the number of bytes read when processing the option extended delta and the option extended length. Moreover, the calculation of the message_left variable, in the case of non-extended option deltas, is incorrect and indicates more data left for processing than provided in the function input. All of these lead to heap-based or stack-based memory location read access that is outside of the intended boundary of the buffer. Depending on the platform-specific memory management mechanisms, it can lead to processing of unintended inputs or system memory access violation errors.

A remote adversary with the ability to send arbitrary CoAP packets to be parsed by Zephyr is able to cause a denial of service. This issue affects: zephyrproject-rtos zephyr version 2.2.0 and later versions.

A vulnerability in the Constrained Application Protocol (CoAP) implementation of Cisco IoT Field Network Director could allow an unauthenticated remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient input validation of incoming CoAP traffic. An attacker could exploit this vulnerability by sending a malformed CoAP packet to an affected device. A successful exploit could allow the attacker to force the CoAP server to stop, interrupting communication to the IoT endpoints.

An integer overflow was discovered in the CoAP library in Arm Mbed OS 5.14.0. The function sn_coap_builder_calc_needed_packet_data_size_2() is used to calculate the required memory for the CoAP message from the sn_coap_hdr_s data structure. Both returned_byte_count and src_coap_msg_ptr->payload_len are of type uint16_t. When added together, the result returned_byte_count can wrap around the maximum uint16_t value. As a result, insufficient buffer space is allocated for the corresponding CoAP message.

Buffer overflows were discovered in the CoAP library in Arm Mbed OS 5.14.0. The CoAP parser is responsible for parsing received CoAP packets. The function sn_coap_parser_options_parse() parses CoAP input linearly using a while loop. Once an option is parsed in a loop, the current point (*packet_data_pptr) is increased correspondingly. The pointer is restricted by the size of the received buffer, as well as by the 0xFF delimiter byte. Inside each while loop, the check of the value of *packet_data_pptr is not strictly enforced. More specifically, inside a loop, *packet_data_pptr could be increased and then dereferenced without checking. Moreover, there are many other functions in the format of sn_coap_parser_****() that do not check whether the pointer is within the bounds of the allocated buffer. All of these lead to heap-based or stack-based buffer overflows, depending on how the CoAP packet buffer is allocated.

coap_decode_option in coap.c in LibNyoci 0.07.00rc1 mishandles certain packets with "Uri-Path: (null)" and consequently allows remote attackers to cause a denial of service (segmentation fault).

The Serialize.deserialize() method in CoAPthon 3.1, 4.0.0, 4.0.1, and 4.0.2 mishandles certain exceptions, leading to a denial of service in applications that use this library (e.g., the standard CoAP server, CoAP client, CoAP reverse proxy, example collect CoAP server and client) when they receive crafted CoAP messages.

The Serialize.deserialize() method in CoAPthon3 1.0 and 1.0.1 mishandles certain exceptions, leading to a denial of service in applications that use this library (e.g., the standard CoAP server, CoAP client, example collect CoAP server and client) when they receive crafted CoAP messages.

In IoTivity through 1.3.1, the CoAP server interface can be used for Distributed Denial of Service attacks using source IP address spoofing and UDP-based traffic amplification. The reflected traffic is 6 times bigger than spoofed requests. This occurs because the construction of a "4.01 Unauthorized" response is mishandled. NOTE: the vendor states "While this is an interesting attack, there is no plan for maintainer to fix, as we are migrating to IoTivity Lite."