{"id":"CVE-2021-21410","aliases":["EUVD-2021-8701"],"status":"published","title":"Out-of-bounds read in the 6LoWPAN implementation","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 (\u003ccode\u003euncompress_hdr_iphc\u003c/code\u003e) 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.","severity":{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.0123,"percentile":0.69357,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-125"],"published":"2021-06-18T21:00:14Z","modified":"2026-06-17T03:35:31Z","products":[{"vendor":"contiki-ng","product":"contiki-ng"}],"references":[{"url":"https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-hhwj-2p59-v8p9","tags":["x_refsource_CONFIRM","x_transferred","Patch","Third Party Advisory"]},{"url":"https://github.com/contiki-ng/contiki-ng/pull/1482","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory"]}],"sources":{"cve":[{"id":"CVE-2021-21410","title":"Out-of-bounds read in the 6LoWPAN implementation","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 (\u003ccode\u003euncompress_hdr_iphc\u003c/code\u003e) 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.","status":"published","published":"2021-06-18T21:00:14Z","modified":"2024-08-03T18:09:16.082Z","cvss":[{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L","level":"high","assessor":"cna"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T14:32:59.802172Z"}],"euvd":[{"id":"EUVD-2021-8701","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 (\u003ccode\u003euncompress_hdr_iphc\u003c/code\u003e) 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.","status":"published","published":"2021-06-18T21:00:14Z","modified":"2024-08-03T18:09:16Z","cvss":[{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L","level":"high"}],"updated_at":"2026-11-03T03:25:06.347262Z"}],"nvd":[{"id":"CVE-2021-21410","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 (\u003ccode\u003euncompress_hdr_iphc\u003c/code\u003e) 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.","status":"published","published":"2021-06-18T21:15:07.947Z","modified":"2026-06-17T03:35:31.237Z","cvss":[{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L","level":"high","assessor":"secondary"},{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","level":"critical","assessor":"primary"},{"version":"2.0","score":6.4,"vector":"AV:N/AC:L/Au:N/C:P/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T14:06:54.892562Z"}]}}