Contiki-NG is an open-source, cross-platform operating system for IoT devices. An unaligned memory access can be triggered in the two RPL implementations of the Contiki-NG operating system. The problem can occur when either one of these RPL implementations is enabled and connected to an RPL instance. If an IPv6 packet containing an odd number of padded bytes before the RPL option, it can cause the rpl_ext_header_hbh_update function to read a 16-bit integer from an odd address. The impact of this unaligned read is architecture-dependent, but can potentially cause the system to crash. The problem has not been patched as of release 4.9, but will be included in the next release. One can apply the changes in Contiki-NG pull request #2962 to patch the system or wait for the next release.

Contiki-NG is an open-source, cross-platform operating system for IoT devices. An out-of-bounds read of 1 byte can be triggered when sending a packet to a device running the Contiki-NG operating system with SNMP enabled. The SNMP module is disabled in the default Contiki-NG configuration. The vulnerability exists in the os/net/app-layer/snmp/snmp-message.c module, where the snmp_message_decode function fails to check the boundary of the message buffer when reading a byte from it immediately after decoding an object identifier (OID). The problem has been patched in Contiki-NG pull request 2937. It will be included in the next release of Contiki-NG. Users are advised to either apply the patch manually or to wait for the next release. A workaround is to disable the SNMP module in the Contiki-NG build configuration.

Contiki-NG is an open-source, cross-platform operating system for IoT devices. An out-of-bounds read of 1 byte can be triggered when sending a packet to a device running the Contiki-NG operating system with SNMP enabled. The SNMP module is disabled in the default Contiki-NG configuration. The vulnerability exists in the os/net/app-layer/snmp/snmp-ber.c module, where the function snmp_ber_decode_string_len_buffer decodes the string length from a received SNMP packet. In one place, one byte is read from the buffer, without checking that the buffer has another byte available, leading to a possible out-of-bounds read. The problem has been patched in Contiki-NG pull request #2936. It will be included in the next release of Contiki-NG. Users are advised to apply the patch manually or to wait for the next release. A workaround is to disable the SNMP module in the Contiki-NG build configuration.

Contiki-NG is an open-source, cross-platform operating system for IoT devices. The Contiki-NG operating system processes source routing headers (SRH) in its two alternative RPL protocol implementations. The IPv6 implementation uses the results of this processing to determine whether an incoming packet should be forwarded to another host. Because of missing validation of the resulting next-hop address, an uncontrolled recursion may occur in the tcpip_ipv6_output function in the os/net/ipv6/tcpip.c module when receiving a packet with a next-hop address that is a local address. Attackers that have the possibility to send IPv6 packets to the Contiki-NG host can therefore trigger deeply nested recursive calls, which can cause a stack overflow. The vulnerability has not been patched in the current release of Contiki-NG, but is expected to be patched in the next release. The problem can be fixed by applying the patch in Contiki-NG pull request #2264. Users are advised to either apply the pat…

Contiki-NG is an open-source, cross-platform operating system for Next-Generation IoT devices. An attacker can trigger out-of-bounds reads in the RPL-Lite implementation of the RPL protocol in the Contiki-NG operating system. This vulnerability is caused by insufficient control of the lengths for DIO and DAO messages, in particular when they contain RPL sub-option headers. The problem has been patched in Contiki-NG 4.9. Users are advised to upgrade. Users unable to upgrade should manually apply the code changes in PR #2484.

Contiki-NG is an open-source, cross-platform operating system for Next-Generation IoT devices. An out-of-bounds read can be caused by an incoming DIO message when using the RPL-Lite implementation in the Contiki-NG operating system. More specifically, the prefix information of the DIO message contains a field that specifies the length of an IPv6 address prefix. The value of this field is not validated, which means that an attacker can set a value that is longer than the maximum prefix length. Subsequently, a memcmp function call that compares different prefixes can be called with a length argument that surpasses the boundary of the array allocated for the prefix, causing an out-of-bounds read. The problem has been patched in the "develop" branch of Contiki-NG, and is expected to be included in the next release. Users are advised to update as soon as they are able to or to manually apply the changes in Contiki-NG pull request #2721.

Contiki-NG is an open-source, cross-platform operating system for Next-Generation IoT devices. An out-of-bounds write exists in the driver for IEEE 802.15.4 radios on nRF platforms in the Contiki-NG operating system. The problem is triggered when parsing radio frames in the `read_frame` function in the `arch/cpu/nrf/net/nrf-ieee-driver-arch.c` module. More specifically, the `read_frame` function performs an incomplete validation of the payload length of the packet, which is a value that can be set by an external party that sends radio packets to a Contiki-NG system. Although the value is validated to be in the range of the MTU length, it is not validated to fit into the given buffer into which the packet will be copied. The problem has been patched in the "develop" branch of Contiki-NG and is expected to be included in subsequent releases. Users are advised to update their develop branch or to update to a subsequent release when available. Users unable to upgrade should consider manua…

Buffer over-read vulnerability in Contiki-NG tinyDTLS through master branch 53a0d97 allows attackers obtain sensitive information via crafted input to dtls_ccm_decrypt_message().

In Contiki 4.5, TCP ISNs are improperly random.

Contiki-NG is an operating system for internet-of-things devices. In versions 4.9 and prior, when a packet is received, the Contiki-NG network stack attempts to start the periodic TCP timer if it is a TCP packet with the SYN flag set. But the implementation does not first verify that a full TCP header has been received. Specifically, the implementation attempts to access the flags field from the TCP buffer in the following conditional expression in the `check_for_tcp_syn` function. For this reason, an attacker can inject a truncated TCP packet, which will lead to an out-of-bound read from the packet buffer. As of time of publication, a patched version is not available. As a workaround, one can apply the changes in Contiki-NG pull request #2510 to patch the system.