CVE-2021-32771: contiki-ng Classic Buffer Overflow

Vulnerability summary

CVE-2021-32771 is a high (CVSS 8.1) Classic Buffer Overflow vulnerability in contiki-ng. EPSS estimates a 1.35% chance of exploitation in the next 30 days, higher than 71.3% of scored vulnerabilities.

Timeline

1. 04-08-2022
   PublishedVulnerability first disclosed.
2. 23-04-2025
   Last modifiedVulnerability information updated.

Description

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.

• CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.