CVE-2021-32771: Contiki-NG

High severity, CVSS 8.1. EPSS: 1.3% chance of exploitation in the next 30 days.

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.

Affected products

• Contiki-NG Contiki-NG: before 4.8 (fixed in 4.8)

Published 2022-08-04. Last modified 2026-06-17.