{
    "CVE_data_meta": {
        "ASSIGNER": "security-advisories@github.com",
        "ID": "CVE-2022-36009",
        "STATE": "PUBLIC",
        "TITLE": "Incorrect parsing of access level in gomatrixserverlib and dendrite"
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "product": {
                        "product_data": [
                            {
                                "product_name": "gomatrixserverlib",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_value": "< 0.9.3 for dendrite"
                                        },
                                        {
                                            "version_value": " < 723fd49 for gomatrixserverlib"
                                        }
                                    ]
                                }
                            }
                        ]
                    },
                    "vendor_name": "matrix-org"
                }
            ]
        }
    },
    "data_format": "MITRE",
    "data_type": "CVE",
    "data_version": "4.0",
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "gomatrixserverlib is a Go library for matrix protocol federation. Dendrite is a Matrix homeserver written in Go, an alternative to Synapse. The power level parsing within gomatrixserverlib was failing to parse the `\"events_default\"` key of the `m.room.power_levels` event, defaulting the event default power level to zero in all cases. Power levels are the matrix terminology for user access level. In rooms where the `\"events_default\"` power level had been changed, this could result in events either being incorrectly authorised or rejected by Dendrite servers. gomatrixserverlib contains a fix as of commit `723fd49` and Dendrite 0.9.3 has been updated accordingly. Matrix rooms where the `\"events_default\"` power level has not been changed from the default of zero are not vulnerable. Users are advised to upgrade. There are no known workarounds for this issue."
            }
        ]
    },
    "impact": {
        "cvss": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 5.0,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L",
            "version": "3.1"
        }
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "CWE-863: Incorrect Authorization"
                    }
                ]
            }
        ]
    },
    "references": {
        "reference_data": [
            {
                "name": "https://github.com/matrix-org/gomatrixserverlib/security/advisories/GHSA-grvv-h2f9-7v9c",
                "refsource": "CONFIRM",
                "url": "https://github.com/matrix-org/gomatrixserverlib/security/advisories/GHSA-grvv-h2f9-7v9c"
            },
            {
                "name": "https://github.com/matrix-org/gomatrixserverlib/commit/723fd495dde835d078b9f2074b6b62c06dea4575",
                "refsource": "MISC",
                "url": "https://github.com/matrix-org/gomatrixserverlib/commit/723fd495dde835d078b9f2074b6b62c06dea4575"
            },
            {
                "name": "https://matrix.org/docs/guides/moderation/#power-levels",
                "refsource": "MISC",
                "url": "https://matrix.org/docs/guides/moderation/#power-levels"
            }
        ]
    },
    "source": {
        "advisory": "GHSA-grvv-h2f9-7v9c",
        "discovery": "UNKNOWN"
    }
}