Contiki-NG is an open-source, cross-platform operating system for Next-Generation IoT devices. The low-power IPv6 network stack of Contiki-NG has a buffer module (os/net/ipv6/uipbuf.c) that processes IPv6 extension headers in incoming data packets. As part of this processing, the function uipbuf_get_next_header casts a pointer to a uip_ext_hdr structure into the packet buffer at different offsets where extension headers are expected to be found, and then reads from this structure. Because of a lack of bounds checking, the casting can be done so that the structure extends beyond the packet's end. Hence, with a carefully crafted packet, it is possible to cause the Contiki-NG system to read data outside the packet buffer. A patch that fixes the vulnerability is included in Contiki-NG 4.8.

Contiki-NG is an open-source, cross-platform operating system for Next-Generation IoT devices. The 6LoWPAN implementation in Contiki-NG may cast a UDP header structure at a certain offset in a packet buffer. The code does not check whether the packet buffer is large enough to fit a full UDP header structure from the offset where the casting is made. Hence, it is possible to cause an out-of-bounds read beyond the packet buffer. The problem affects anyone running devices with Contiki-NG versions previous to 4.8, and which may receive 6LoWPAN packets from external parties. The problem has been patched in Contiki-NG version 4.8.

Contiki-NG is an open-source, cross-platform operating system for IoT devices. In the RPL-Classic routing protocol implementation in the Contiki-NG operating system, an incoming DODAG Information Option (DIO) control message can contain a prefix information option with a length parameter. The value of the length parameter is not validated, however, and it is possible to cause a buffer overflow when copying the prefix in the set_ip_from_prefix function. This vulnerability affects anyone running a Contiki-NG version prior to 4.7 that can receive RPL DIO messages from external parties. To obtain a patched version, users should upgrade to Contiki-NG 4.7 or later. There are no workarounds for this issue.

Contiki-NG is an open-source, cross-platform operating system for IoT devices. Because of insufficient validation of IPv6 neighbor discovery options in Contiki-NG, attackers can send neighbor solicitation packets that trigger an out-of-bounds read. The problem exists in the module os/net/ipv6/uip-nd6.c, where memory read operations from the main packet buffer, <code>uip_buf</code>, are not checked if they go out of bounds. In particular, this problem can occur when attempting to read the 2-byte option header and the Source Link-Layer Address Option (SLLAO). This attack requires ipv6 be enabled for the network. The problem has been patched in the develop branch of Contiki-NG. The upcoming 4.8 release of Contiki-NG will include the patch.Users unable to upgrade may apply the patch in Contiki-NG PR #1654.

Contiki-NG is an open-source, cross-platform operating system for IoT devices. In affected versions it is possible to cause a buffer overflow when copying an IPv6 address prefix in the RPL-Classic implementation in Contiki-NG. In order to trigger the vulnerability, the Contiki-NG system must have joined an RPL DODAG. After that, an attacker can send a DAO packet with a Target option that contains a prefix length larger than 128 bits. The problem was fixed after the release of Contiki-NG 4.7. Users unable to upgrade may apply the patch in Contiki-NG PR #1615.

A buffer overflow in os/net/mac/ble/ble-l2cap.c in the BLE stack in Contiki-NG 4.4 and earlier allows an attacker to execute arbitrary code via malicious L2CAP frames.

An out-of-bounds read in the SNMP stack in Contiki-NG 4.4 and earlier allows an attacker to cause a denial of service and potentially disclose information via crafted SNMP packets to snmp_ber_decode_string_len_buffer in os/net/app-layer/snmp/snmp-ber.c.

In Contiki 3.0, Telnet option negotiation is mishandled. During negotiation between a server and a client, the server may fail to give the WILL/WONT or DO/DONT response for DO and WILL commands because of improper handling of exception condition, which leads to property violations and denial of service. Specifically, a server sometimes sends no response, because a fixed buffer space is available for all responses and that space may have been exhausted.

In Contiki 3.0, a buffer overflow in the Telnet service allows remote attackers to cause a denial of service because the ls command is mishandled when a directory has many files with long names.

In Contiki 3.0, a Telnet server that silently quits (before disconnection with clients) leads to connected clients entering an infinite loop and waiting forever, which may cause excessive CPU consumption.