CVE-2020-25685

{"id": "CVE-2020-25685", "metrics": {"cvssMetricV2": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"version": "2.0", "baseScore": 4.3, "accessVector": "NETWORK", "vectorString": "AV:N/AC:M/Au:N/C:N/I:P/A:N", "authentication": "NONE", "integrityImpact": "PARTIAL", "accessComplexity": "MEDIUM", "availabilityImpact": "NONE", "confidentialityImpact": "NONE"}, "acInsufInfo": false, "impactScore": 2.9, "baseSeverity": "MEDIUM", "obtainAllPrivilege": false, "exploitabilityScore": 8.6, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 3.7, "attackVector": "NETWORK", "baseSeverity": "LOW", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 1.4, "exploitabilityScore": 2.2}]}, "published": "2021-01-20T16:15:14.303", "references": [{"url": "https://bugzilla.redhat.com/show_bug.cgi?id=1889688", "tags": ["Issue Tracking", "Patch", "Third Party Advisory"], "source": "secalert@redhat.com"}, {"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/", "source": "secalert@redhat.com"}, {"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/", "source": "secalert@redhat.com"}, {"url": "https://security.gentoo.org/glsa/202101-17", "tags": ["Third Party Advisory"], "source": "secalert@redhat.com"}, {"url": "https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61", "tags": ["Third Party Advisory"], "source": "secalert@redhat.com"}, {"url": "https://www.debian.org/security/2021/dsa-4844", "tags": ["Third Party Advisory"], "source": "secalert@redhat.com"}, {"url": "https://www.jsof-tech.com/disclosures/dnspooq/", "tags": ["Third Party Advisory"], "source": "secalert@redhat.com"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-326"}]}, {"type": "Secondary", "source": "secalert@redhat.com", "description": [{"lang": "en", "value": "CWE-326"}]}], "descriptions": [{"lang": "en", "value": "A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in forward.c:reply_query(), which is the forwarded query that matches the reply, by only using a weak hash of the query name. Due to the weak hash (CRC32 when dnsmasq is compiled without DNSSEC, SHA-1 when it is) this flaw allows an off-path attacker to find several different domains all having the same hash, substantially reducing the number of attempts they would have to perform to forge a reply and get it accepted by dnsmasq. This is in contrast with RFC5452, which specifies that the query name is one of the attributes of a query that must be used to match a reply. This flaw could be abused to perform a DNS Cache Poisoning attack. If chained with CVE-2020-25684 the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity."}, {"lang": "es", "value": "Se encontr\u00f3 un fallo en dnsmasq versiones anteriores a 2.83. Al obtener una respuesta de una consulta reenviada, dnsmasq comprueba en forward.c:reply_query(), que es la consulta reenviada que coincide con la respuesta, usando solo un hash d\u00e9bil del nombre de la consulta. Debido al hash d\u00e9bil (CRC32 cuando dnsmasq se compila sin DNSSEC, SHA-1 cuando lo es), este fallo permite a un atacante fuera de ruta encontrar varios dominios diferentes que tengan el mismo hash, reduciendo sustancialmente el n\u00famero de intentos que tendr\u00edan que realizar para falsificar una respuesta y conseguir que dnsmasq la acepte. Esto contrasta con RFC5452, que especifica que el nombre de la consulta es uno de los atributos de una consulta que debe ser usada para hacer coincidir una respuesta. Se puede abusar de este fallo para realizar un ataque de envenenamiento de cach\u00e9 de DNS. Si se encadena con CVE-2020-25684, se reduce la complejidad del ataque de un ataque con \u00e9xito"}], "lastModified": "2023-11-07T03:20:22.197", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:thekelleys:dnsmasq:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F38115DF-0F5C-442D-83D4-1125AAB4E2B7", "versionEndExcluding": "2.83"}], "operator": "OR"}]}, {"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "36D96259-24BD-44E2-96D9-78CE1D41F956"}, {"criteria": "cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E460AA51-FCDA-46B9-AE97-E6676AA5E194"}], "operator": "OR"}]}, {"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73"}], "operator": "OR"}]}, {"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "2E5C0DA1-5E51-40F1-82FE-CF7E391C07E4", "versionEndExcluding": "4.21.14m", "versionStartIncluding": "4.21"}, {"criteria": "cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "206E795F-BFE9-4AB9-A35F-60AC911F38E4", "versionEndExcluding": "4.22.9m", "versionStartIncluding": "4.22"}, {"criteria": "cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6FA15712-F804-4060-99C0-7370D6111B83", "versionEndExcluding": "4.23.7m", "versionStartIncluding": "4.23"}, {"criteria": "cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "21A321F5-CB56-4258-BB30-6753EECB89DD", "versionEndExcluding": "4.24.5m", "versionStartIncluding": "4.24"}, {"criteria": "cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "9445AF76-6AE4-46A6-A470-979ADBB19EE2", "versionEndExcluding": "4.25.2f", "versionStartIncluding": "4.25"}], "operator": "OR"}]}], "sourceIdentifier": "secalert@redhat.com"}