{
  "id": "CVE-2021-32778",
  "sourceIdentifier": "security-advisories@github.com",
  "published": "2021-08-24T21:15:09.553",
  "lastModified": "2022-06-15T15:49:59.423",
  "vulnStatus": "Analyzed",
  "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\u2019s 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 c\u00f3digo abierto y un bus de comunicaci\u00f3n dise\u00f1ado 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 n\u00famero de flujos. Los despliegues son susceptibles a una Denegaci\u00f3n de Servicio cuando Envoy est\u00e1 configurado con un alto l\u00edmite de flujos concurrentes H/2. Un atacante que desee explotar esta vulnerabilidad necesitar\u00eda un cliente que abriera y cerrara un gran n\u00famero 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 soluci\u00f3n, los usuarios pueden limitar el n\u00famero de sue\u00f1os HTTP/2 simult\u00e1neos para los pares ascendentes y descendentes a un n\u00famero bajo, es decir, 100."
    }
  ],
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        "type": "Primary",
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          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH"
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        "exploitabilityScore": 3.9,
        "impactScore": 3.6
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          "accessVector": "NETWORK",
          "accessComplexity": "LOW",
          "authentication": "NONE",
          "confidentialityImpact": "NONE",
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          "baseScore": 5.0
        },
        "baseSeverity": "MEDIUM",
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        "obtainAllPrivilege": false,
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        "obtainOtherPrivilege": false,
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          "operator": "OR",
          "negate": false,
          "cpeMatch": [
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              "vulnerable": true,
              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
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  "references": [
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      "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-3xh3-33v5-chcc",
      "source": "security-advisories@github.com",
      "tags": [
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    {
      "url": "https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history",
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