{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2021-26887",
        "ASSIGNER": "secure@microsoft.com",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "<p>An elevation of privilege vulnerability exists in Microsoft Windows when Folder redirection has been enabled via Group Policy. When folder redirection file server is co-located with Terminal server, an attacker who successfully exploited the vulnerability would be able to begin redirecting another user's personal data to a created folder.</p>\n<p>To exploit the vulnerability, an attacker can create a new folder under the Folder Redirection root path and create a junction on a newly created User folder. When the new user logs in, Folder Redirection would start redirecting to the folder and copying personal data.</p>\n<p>This elevation of privilege vulnerability can only be addressed by reconfiguring Folder Redirection with Offline files and restricting permissions, and NOT via a security update for affected Windows Servers. See the <strong>FAQ</strong> section of this CVE for configuration guidance.</p>\n"
            }
        ]
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "Elevation of Privilege"
                    }
                ]
            }
        ]
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "vendor_name": "Microsoft",
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Windows 10 Version 2004",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server version 2004",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows 10 Version 20H2",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server version 20H2",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows 10 Version 1803",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows 10 Version 1809",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server 2019",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server 2019 (Server Core installation)",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows 10 Version 1909",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server, version 1909 (Server Core installation)",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows 10 Version 1507",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows 10 Version 1607",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server 2016",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server 2016 (Server Core installation)",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows 7",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows 7 Service Pack 1",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows 8.1",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server 2008 Service Pack 2",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server 2008 Service Pack 2 (Server Core installation)",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server 2008  Service Pack 2",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server 2008 R2 Service Pack 1",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server 2008 R2 Service Pack 1 (Server Core installation)",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server 2012",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_name": "6.2.0",
                                            "version_value": "publication"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server 2012 (Server Core installation)",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_name": "6.2.0",
                                            "version_value": "publication"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server 2012 R2",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Windows Server 2012 R2 (Server Core installation)",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "N/A"
                                        }
                                    ]
                                }
                            }
                        ]
                    }
                }
            ]
        }
    },
    "references": {
        "reference_data": [
            {
                "url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26887",
                "refsource": "MISC",
                "name": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26887"
            }
        ]
    },
    "impact": {
        "cvss": [
            {
                "version": "3.1",
                "baseSeverity": "HIGH",
                "baseScore": 7.8,
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C"
            }
        ]
    }
}