{"affected":[{"affectedData":[{"product":"Nextcloud Server","vendor":"Nextcloud","versions":[{"status":"affected","version":"<13.0.3, <12.0.8"}]}],"source":"support@hackerone.com"}],"configurations":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*","matchCriteriaId":"8CEE07AB-CFB8-41CB-85E7-06FF3977DD2B","versionEndExcluding":"12.0.8","vulnerable":true},{"criteria":"cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*","matchCriteriaId":"4C66EEA7-59A5-4F3B-ADC3-5A7422B1FBC0","versionEndExcluding":"13.0.3","versionStartIncluding":"13.0.0","vulnerable":true}],"negate":false,"operator":"OR"}]}],"cveTags":[],"descriptions":[{"lang":"en","value":"Nextcloud Server before 12.0.8 and 13.0.3 suffer from improper authentication on the OAuth2 token endpoint. Missing checks potentially allowed handing out new tokens in case the OAuth2 client was partly compromised."},{"lang":"es","value":"Nextcloud Server en versiones anteriores a la 12.0.8 y la 13.0.3 sufre de una autorización incorrecta en el endpoint del token OAuth2. La falta de comprobaciones pudo permitir la repartición de nuevos tokens en caso de que el cliente OAuth2 se hubiese visto parcialmente comprometido."}],"id":"CVE-2018-3761","lastModified":"2026-06-17T01:57:47.213","metrics":{"cvssMetricV2":[{"acInsufInfo":false,"baseSeverity":"MEDIUM","cvssData":{"accessComplexity":"MEDIUM","accessVector":"NETWORK","authentication":"NONE","availabilityImpact":"NONE","baseScore":5.8,"confidentialityImpact":"PARTIAL","integrityImpact":"PARTIAL","vectorString":"AV:N/AC:M/Au:N/C:P/I:P/A:N","version":"2.0"},"exploitabilityScore":8.6,"impactScore":4.9,"obtainAllPrivilege":false,"obtainOtherPrivilege":false,"obtainUserPrivilege":false,"source":"nvd@nist.gov","type":"Primary","userInteractionRequired":true}],"cvssMetricV31":[{"cvssData":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":8.1,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N","version":"3.1"},"exploitabilityScore":2.8,"impactScore":5.2,"source":"nvd@nist.gov","type":"Primary"}]},"published":"2018-07-05T16:29:00.407","references":[{"source":"support@hackerone.com","tags":["Third Party Advisory"],"url":"https://hackerone.com/reports/343111"},{"source":"support@hackerone.com","tags":["Broken Link","Vendor Advisory"],"url":"https://nextcloud.com/security/advisory/?id=nc-sa-2018-003"},{"source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Third Party Advisory"],"url":"https://hackerone.com/reports/343111"},{"source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Broken Link","Vendor Advisory"],"url":"https://nextcloud.com/security/advisory/?id=nc-sa-2018-003"}],"sourceIdentifier":"support@hackerone.com","vulnStatus":"Modified","weaknesses":[{"description":[{"lang":"en","value":"CWE-287"}],"source":"support@hackerone.com","type":"Secondary"},{"description":[{"lang":"en","value":"CWE-287"}],"source":"nvd@nist.gov","type":"Primary"}]}