{
    "CVE_data_meta": {
        "ASSIGNER": "security-advisories@github.com",
        "ID": "CVE-2021-32778",
        "STATE": "PUBLIC",
        "TITLE": "Excessive CPU utilization when closing HTTP/2 streams"
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "product": {
                        "product_data": [
                            {
                                "product_name": "envoy",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_value": ">= 1.19.0, < 1.19.1"
                                        },
                                        {
                                            "version_value": ">= 1.18.0, < 1.18.4"
                                        },
                                        {
                                            "version_value": ">= 1.17.0, < 1.17.4"
                                        },
                                        {
                                            "version_value": ">= 1.16.0, < 1.16.5"
                                        }
                                    ]
                                }
                            }
                        ]
                    },
                    "vendor_name": "envoyproxy"
                }
            ]
        }
    },
    "data_format": "MITRE",
    "data_type": "CVE",
    "data_version": "4.0",
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "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."
            }
        ]
    },
    "impact": {
        "cvss": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 5.8,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L",
            "version": "3.1"
        }
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "CWE-834: Excessive Iteration"
                    }
                ]
            }
        ]
    },
    "references": {
        "reference_data": [
            {
                "name": "https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history",
                "refsource": "MISC",
                "url": "https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history"
            },
            {
                "name": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-3xh3-33v5-chcc",
                "refsource": "CONFIRM",
                "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-3xh3-33v5-chcc"
            }
        ]
    },
    "source": {
        "advisory": "GHSA-3xh3-33v5-chcc",
        "discovery": "UNKNOWN"
    }
}