Contiki-NG is an operating system for internet of things devices. In version 4.8 and prior, when processing ICMP DAO packets in the daoinputstoring function, the Contiki-NG OS does not verify that the packet buffer is big enough to contain the bytes it needs before accessing them. Up to 16 bytes can be read out of bounds in the daoinputstoring function. An attacker can truncate an ICMP packet so that it does not contain enough data, leading to an out-of-bounds read on these lines. The problem has been patched in the "develop" branch of Contiki-NG, and is expected to be included in release 4.9. As a workaround, one can apply the changes in Contiki-NG pull request #2435 to patch the system.

Contiki-NG is an open-source, cross-platform operating system for IoT devices. When reading the TCP MSS option value from an incoming packet, the Contiki-NG OS does not verify that certain buffer indices to read from are within the bounds of the IPv6 packet buffer, uipbuf. In particular, there is a 2-byte buffer read in the module os/net/ipv6/uip6.c. The buffer is indexed using 'UIPIPTCPHLEN + 2 + c' and 'UIPIPTCPHLEN + 3 + c', but the uipbuf buffer may not have enough data, resulting in a 2-byte read out of bounds. The problem has been patched in the "develop" branch of Contiki-NG, and is expected to be included in release 4.9. Users are advised to watch for the 4.9 release and to upgrade when it becomes available. There are no workarounds for this vulnerability aside from manually patching with the diff in commit cde4e9839.