{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2023-39953",
        "ASSIGNER": "security-advisories@github.com",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "user_oidc provides the OIDC connect user backend for Nextcloud, an open-source cloud platform. Starting in version 1.0.0 and prior to version 1.3.3, missing verification of the issuer would have allowed an attacker to perform a man-in-the-middle attack returning corrupted or known token they also have access to. user_oidc 1.3.3 contains a patch. No known workarounds are available."
            }
        ]
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "CWE-303: Incorrect Implementation of Authentication Algorithm",
                        "cweId": "CWE-303"
                    }
                ]
            }
        ]
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "vendor_name": "nextcloud",
                    "product": {
                        "product_data": [
                            {
                                "product_name": "security-advisories",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": ">= 1.0.0, < 1.3.3"
                                        }
                                    ]
                                }
                            }
                        ]
                    }
                }
            ]
        }
    },
    "references": {
        "reference_data": [
            {
                "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xx3h-v363-q36j",
                "refsource": "MISC",
                "name": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xx3h-v363-q36j"
            },
            {
                "url": "https://github.com/nextcloud/user_oidc/pull/642",
                "refsource": "MISC",
                "name": "https://github.com/nextcloud/user_oidc/pull/642"
            },
            {
                "url": "https://hackerone.com/reports/2021684",
                "refsource": "MISC",
                "name": "https://hackerone.com/reports/2021684"
            }
        ]
    },
    "source": {
        "advisory": "GHSA-xx3h-v363-q36j",
        "discovery": "UNKNOWN"
    },
    "impact": {
        "cvss": [
            {
                "attackComplexity": "HIGH",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 4.8,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "LOW",
                "integrityImpact": "LOW",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
                "version": "3.1"
            }
        ]
    }
}