{"id":"CVE-2021-32771","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-32771","generatedAt":"2026-10-27T21:19:51.142Z","title":"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.","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.","published":"2022-08-04T21:15:08.000Z","lastModified":"2026-06-17T03:53:36.000Z","status":"Modified","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":8.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-120"],"affected":["contiki-ng/contiki-ng"],"epss":{"score":0.01353,"percentile":0.71385,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (1.35%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/contiki-ng/contiki-ng/pull/1615","tags":["Patch","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/contiki-ng/contiki-ng/pull/1615/commits/587ae59956e00316fd44fd7072ac3a6a07b4b20f","tags":["Patch","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/contiki-ng/contiki-ng/releases/tag/release%2Fv4.8","tags":["Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-jqjf-v7v9-xp6w","tags":["Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/contiki-ng/contiki-ng/pull/1615","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/contiki-ng/contiki-ng/pull/1615/commits/587ae59956e00316fd44fd7072ac3a6a07b4b20f","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/contiki-ng/contiki-ng/releases/tag/release%2Fv4.8","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-jqjf-v7v9-xp6w","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-32771","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}