{"schemaVersion":3,"id":"CVE-2021-21410","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"Contiki-NG is an open-source, cross-platform operating system for Next-Generation IoT devices. An out-of-bounds read can be triggered by 6LoWPAN packets sent to devices running Contiki-NG 4.6 and prior. The IPv6 header decompression function (<code>uncompress_hdr_iphc</code>) does not perform proper boundary checks when reading from the packet buffer. Hence, it is possible to construct a compressed 6LoWPAN packet that will read more bytes than what is available from the packet buffer. As of time of publication, there is not a release with a patch available. Users can apply the patch for this vulnerability out-of-band as a workaround.","dates":{"published":"2021-06-18T21:00:14.000Z","modified":"2024-08-03T18:09:16.082Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":9.1,"severity":"critical","version":"3.1","versionLabel":"v3.1","source":"NVD","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":8.2,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":9.1,"severity":"critical","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","exploitability":null,"impact":null,"computed":false},{"version":"2.0","versionLabel":"v2.0","source":"NVD","score":6.4,"severity":"medium","vector":"AV:N/AC:L/Au:N/C:P/I:N/A:P","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.0123,"percentile":0.68684,"severity":"low","asOf":"2026-10-21T00:00:00.000Z","change":{"pp":0,"baselineDate":"2026-09-21T00:00:00.000Z","baselineScore":0.0123},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.0123,"percentile":0.68684}],"last30":[{"date":"2026-09-21T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.0123,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.0123,"perce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