{"api_version":"1","generated_at":"2026-07-23T22:02:25+00:00","cve":"CVE-2021-21257","urls":{"html":"https://cve.report/CVE-2021-21257","api":"https://cve.report/api/cve/CVE-2021-21257.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2021-21257","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-21257"},"summary":{"title":"CVE-2021-21257","description":"Contiki-NG is an open-source, cross-platform operating system for internet of things devices. The RPL-Classic and RPL-Lite implementations in the Contiki-NG operating system versions prior to 4.6 do not validate the address pointer in the RPL source routing header This makes it possible for an attacker to cause out-of-bounds writes with packets injected into the network stack. Specifically, the problem lies in the rpl_ext_header_srh_update function in the two rpl-ext-header.c modules for RPL-Classic and RPL-Lite respectively. The addr_ptr variable is calculated using an unvalidated CMPR field value from the source routing header. An out-of-bounds write can be triggered on line 151 in os/net/routing/rpl-lite/rpl-ext-header.c and line 261 in os/net/routing/rpl-classic/rpl-ext-header.c, which contain the following memcpy call with addr_ptr as destination. The problem has been patched in Contiki-NG 4.6. Users can apply a patch out-of-band as a workaround.","state":"PUBLIC","assigner":"security-advisories@github.com","published_at":"2021-06-18 21:15:00","updated_at":"2021-06-24 19:35:00"},"problem_types":["CWE-787"],"metrics":[],"references":[{"url":"https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-mvc7-9p4q-c5cm","name":"https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-mvc7-9p4q-c5cm","refsource":"CONFIRM","tags":[],"title":"Out-of-bounds write in RPL-Classic and RPL-Lite · Advisory · contiki-ng/contiki-ng · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://github.com/contiki-ng/contiki-ng/pull/1431","name":"https://github.com/contiki-ng/contiki-ng/pull/1431","refsource":"MISC","tags":[],"title":"Validate the address pointer in the source routing header by nvt · Pull Request #1431 · contiki-ng/contiki-ng · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-21257","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21257","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2021","cve_id":"21257","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"contiki-ng","cpe5":"contiki-ng","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"CVE_data_meta":{"ASSIGNER":"security-advisories@github.com","ID":"CVE-2021-21257","STATE":"PUBLIC","TITLE":"Out-of-bounds write in RPL-Classic and RPL-Lite"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"contiki-ng","version":{"version_data":[{"version_value":"< 4.6"}]}}]},"vendor_name":"contiki-ng"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"Contiki-NG is an open-source, cross-platform operating system for internet of things devices. The RPL-Classic and RPL-Lite implementations in the Contiki-NG operating system versions prior to 4.6 do not validate the address pointer in the RPL source routing header This makes it possible for an attacker to cause out-of-bounds writes with packets injected into the network stack. Specifically, the problem lies in the rpl_ext_header_srh_update function in the two rpl-ext-header.c modules for RPL-Classic and RPL-Lite respectively. The addr_ptr variable is calculated using an unvalidated CMPR field value from the source routing header. An out-of-bounds write can be triggered on line 151 in os/net/routing/rpl-lite/rpl-ext-header.c and line 261 in os/net/routing/rpl-classic/rpl-ext-header.c, which contain the following memcpy call with addr_ptr as destination. The problem has been patched in Contiki-NG 4.6. Users can apply a patch out-of-band as a workaround."}]},"impact":{"cvss":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":8.2,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L","version":"3.1"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-787: Out-of-bounds Write"}]}]},"references":{"reference_data":[{"name":"https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-mvc7-9p4q-c5cm","refsource":"CONFIRM","url":"https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-mvc7-9p4q-c5cm"},{"name":"https://github.com/contiki-ng/contiki-ng/pull/1431","refsource":"MISC","url":"https://github.com/contiki-ng/contiki-ng/pull/1431"}]},"source":{"advisory":"GHSA-mvc7-9p4q-c5cm","discovery":"UNKNOWN"}},"nvd":{"publishedDate":"2021-06-18 21:15:00","lastModifiedDate":"2021-06-24 19:35:00","problem_types":["CWE-787"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6},"baseMetricV2":{"cvssV2":{"version":"2.0","vectorString":"AV:N/AC:L/Au:N/C:N/I:N/A:P","accessVector":"NETWORK","accessComplexity":"LOW","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"PARTIAL","baseScore":5},"severity":"MEDIUM","exploitabilityScore":10,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:contiki-ng:contiki-ng:*:*:*:*:*:*:*:*","versionEndExcluding":"4.6","cpe_name":[]}]}]}},"legacy_mitre":{"record":{"CveYear":"2021","CveId":"21257","Ordinal":"195383","Title":"CVE-2021-21257","CVE":"CVE-2021-21257","Year":"2021"},"notes":[{"CveYear":"2021","CveId":"21257","Ordinal":"1","NoteData":"Contiki-NG is an open-source, cross-platform operating system for internet of things devices. The RPL-Classic and RPL-Lite implementations in the Contiki-NG operating system versions prior to 4.6 do not validate the address pointer in the RPL source routing header This makes it possible for an attacker to cause out-of-bounds writes with packets injected into the network stack. Specifically, the problem lies in the rpl_ext_header_srh_update function in the two rpl-ext-header.c modules for RPL-Classic and RPL-Lite respectively. The addr_ptr variable is calculated using an unvalidated CMPR field value from the source routing header. An out-of-bounds write can be triggered on line 151 in os/net/routing/rpl-lite/rpl-ext-header.c and line 261 in os/net/routing/rpl-classic/rpl-ext-header.c, which contain the following memcpy call with addr_ptr as destination. The problem has been patched in Contiki-NG 4.6. Users can apply a patch out-of-band as a workaround.","Type":"Description","Title":null},{"CveYear":"2021","CveId":"21257","Ordinal":"2","NoteData":"2021-06-18","Type":"Other","Title":"Published"},{"CveYear":"2021","CveId":"21257","Ordinal":"3","NoteData":"2021-06-18","Type":"Other","Title":"Modified"}]}}}