{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-08-01T07:21:08.329","vulnerabilities":[{"cve":{"id":"CVE-2021-32778","sourceIdentifier":"security-advisories@github.com","published":"2021-08-24T21:15:09.553","lastModified":"2026-06-17T03:53:36.730","vulnStatus":"Modified","cveTags":[],"descriptions":[{"lang":"en","value":"Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. In affected versions envoy’s procedure for resetting a HTTP/2 stream has O(N^2) complexity, leading to high CPU utilization when a large number of streams are reset. Deployments are susceptible to Denial of Service when Envoy is configured with high limit on H/2 concurrent streams. An attacker wishing to exploit this vulnerability would require a client opening and closing a large number of H/2 streams. Envoy versions 1.19.1, 1.18.4, 1.17.4, 1.16.5 contain fixes to reduce time complexity of resetting HTTP/2 streams. As a workaround users may limit the number of simultaneous HTTP/2 dreams for upstream and downstream peers to a low number, i.e. 100."},{"lang":"es","value":"Envoy es un proxy L7 de código abierto y un bus de comunicación diseñado para grandes arquitecturas modernas orientadas a servicios. En las versiones afectadas, el procedimiento de Envoy para restablecer un flujo HTTP/2 presenta una complejidad O(N^2), conllevando a un alto uso de la CPU cuando se restablece un gran número de flujos. Los despliegues son susceptibles a una Denegación de Servicio cuando Envoy está configurado con un alto límite de flujos concurrentes H/2. Un atacante que desee explotar esta vulnerabilidad necesitaría un cliente que abriera y cerrara un gran número de flujos H/2. Envoy  versiones 1.19.1, 1.18.4, 1.17.4 y 1.16.5, contienen correcciones para reducir la complejidad del tiempo de restablecimiento de los flujos HTTP/2. Como solución, los usuarios pueden limitar el número de sueños HTTP/2 simultáneos para los pares ascendentes y descendentes a un número bajo, es decir, 100."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"envoyproxy","product":"envoy","versions":[{"version":">= 1.19.0, < 1.19.1","status":"affected"},{"version":">= 1.18.0, < 1.18.4","status":"affected"},{"version":">= 1.17.0, < 1.17.4","status":"affected"},{"version":">= 1.16.0, < 1.16.5","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L","baseScore":5.8,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW"},"exploitabilityScore":3.9,"impactScore":1.4},{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}],"cvssMetricV2":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"2.0","vectorString":"AV:N/AC:L/Au:N/C:N/I:N/A:P","baseScore":5.0,"accessVector":"NETWORK","accessComplexity":"LOW","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"PARTIAL"},"baseSeverity":"MEDIUM","exploitabilityScore":10.0,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-834"}]},{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"CWE-834"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*","versionStartIncluding":"1.16.0","versionEndExcluding":"1.16.5","matchCriteriaId":"AFC3BF7F-5B28-4765-8C6F-E2437A4B425D"},{"vulnerable":true,"criteria":"cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*","versionStartIncluding":"1.17.0","versionEndExcluding":"1.17.4","matchCriteriaId":"83547329-1394-417F-93DB-70C1A9D173B0"},{"vulnerable":true,"criteria":"cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*","versionStartIncluding":"1.18.0","versionEndExcluding":"1.18.4","matchCriteriaId":"D7376E28-9915-4CA1-A5DB-40874D10E781"},{"vulnerable":true,"criteria":"cpe:2.3:a:envoyproxy:envoy:1.19.0:*:*:*:*:*:*:*","matchCriteriaId":"1968AA35-60E2-4A00-84A0-617738B55D33"}]}]}],"references":[{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-3xh3-33v5-chcc","source":"security-advisories@github.com","tags":["Third Party Advisory"]},{"url":"https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history","source":"security-advisories@github.com","tags":["Release Notes","Vendor Advisory"]},{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-3xh3-33v5-chcc","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Third Party Advisory"]},{"url":"https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Release Notes","Vendor Advisory"]}]}}]}