{"dataType": "CVE_RECORD", "dataVersion": "5.0", "cveMetadata": {"state": "PUBLISHED", "cveId": "CVE-2020-27213", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "dateUpdated": "2023-10-10T16:28:06.631286", "dateReserved": "2020-10-19T00:00:00", "datePublished": "2023-10-10T00:00:00"}, "containers": {"cna": {"providerMetadata": {"orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre", "dateUpdated": "2023-10-10T16:28:06.631286"}, "descriptions": [{"lang": "en", "value": "An issue was discovered in Ethernut Nut/OS 5.1. The code that generates Initial Sequence Numbers (ISNs) for TCP connections derives the ISN from an insufficiently random source. As a result, an attacker may be able to determine the ISN of current and future TCP connections and either hijack existing ones or spoof future ones. While the ISN generator seems to adhere to RFC 793 (where a global 32-bit counter is incremented roughly every 4 microseconds), proper ISN generation should aim to follow at least the specifications outlined in RFC 6528."}], "affected": [{"vendor": "n/a", "product": "n/a", "versions": [{"version": "n/a", "status": "affected"}]}], "references": [{"url": "http://www.ethernut.de/en/download/index.html"}, {"url": "http://lists.egnite.de/mailman/listinfo/en-nut-announce"}, {"url": "https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01"}, {"url": "https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks/"}], "problemTypes": [{"descriptions": [{"type": "text", "lang": "en", "description": "n/a"}]}]}}}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:ethernut:nut\\/os:5.1:*:*:*:*:*:*:*", "matchCriteriaId": "33F926DD-C48D-4FB6-9CEC-E48DC7FDA4D7", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "descriptions": [{"lang": "en", "value": "An issue was discovered in Ethernut Nut/OS 5.1. The code that generates Initial Sequence Numbers (ISNs) for TCP connections derives the ISN from an insufficiently random source. As a result, an attacker may be able to determine the ISN of current and future TCP connections and either hijack existing ones or spoof future ones. While the ISN generator seems to adhere to RFC 793 (where a global 32-bit counter is incremented roughly every 4 microseconds), proper ISN generation should aim to follow at least the specifications outlined in RFC 6528."}, {"lang": "es", "value": "Se descubri\u00f3 un problema en Ethernut Nut/OS 5.1. El c\u00f3digo que genera Initial Sequence Numbers (ISN) para conexiones TCP deriva el ISN de una fuente insuficientemente aleatoria. Como resultado, un atacante puede determinar el ISN de las conexiones TCP actuales y futuras y secuestrar las existentes o falsificar las futuras. Si bien el generador de ISN parece cumplir con RFC 793 (donde un contador global de 32 bits se incrementa aproximadamente cada 4 microsegundos), la generaci\u00f3n de ISN adecuada debe aspirar a seguir al menos las especificaciones descritas en RFC 6528."}], "id": "CVE-2020-27213", "lastModified": "2023-10-27T19:34:58.647", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.5, "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:N", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2023-10-10T17:15:10.337", "references": [{"source": "cve@mitre.org", "tags": ["Not Applicable"], "url": "http://lists.egnite.de/mailman/listinfo/en-nut-announce"}, {"source": "cve@mitre.org", "tags": ["Release Notes"], "url": "http://www.ethernut.de/en/download/index.html"}, {"source": "cve@mitre.org", "tags": ["Third Party Advisory", "US Government Resource"], "url": "https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01"}, {"source": "cve@mitre.org", "tags": ["Exploit", "Third Party Advisory"], "url": "https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks/"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-330"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{}