cvelist/2021/28xxx/CVE-2021-28702.json

{
    "CVE_data_meta": {
        "ASSIGNER": "security@xen.org",
        "ID": "CVE-2021-28702",
        "STATE": "PUBLIC"
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "product": {
                        "product_data": [
                            {
                                "product_name": "xen",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "?<",
                                            "version_value": "4.12"
                                        },
                                        {
                                            "version_affected": ">=",
                                            "version_value": "4.12.x"
                                        },
                                        {
                                            "version_affected": "!>",
                                            "version_value": "xen-unstable"
                                        }
                                    ]
                                }
                            }
                        ]
                    },
                    "vendor_name": "Xen"
                }
            ]
        }
    },
    "configuration": {
        "configuration_data": {
            "description": {
                "description_data": [
                    {
                        "lang": "eng",
                        "value": "All versions of Xen from at least 4.4 onwards are vulnerable.\n\nOnly Intel x86 systems are affected.  AMD x86 systems, and Arm\nsystems, are all unaffected.\n\nOnly systems using PCI passthrough are affected.  (And then, only if\nthe assigned devices have RMRRs, but whether a device advertises RMRRs\nis not easy to discern.)"
                    }
                ]
            }
        }
    },
    "data_format": "MITRE",
    "data_type": "CVE",
    "data_version": "4.0",
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "PCI devices with RMRRs not deassigned correctly Certain PCI devices in a system might be assigned Reserved Memory Regions (specified via Reserved Memory Region Reporting, \"RMRR\"). These are typically used for platform tasks such as legacy USB emulation. If such a device is passed through to a guest, then on guest shutdown the device is not properly deassigned. The IOMMU configuration for these devices which are not properly deassigned ends up pointing to a freed data structure, including the IO Pagetables. Subsequent DMA or interrupts from the device will have unpredictable behaviour, ranging from IOMMU faults to memory corruption."
            }
        ]
    },
    "impact": {
        "impact_data": {
            "description": {
                "description_data": [
                    {
                        "lang": "eng",
                        "value": "Administrators of guests which have been assigned RMRR-using PCI\ndevices can cause denial of service and other problems, possibly\nincluding escalation of privilege."
                    }
                ]
            }
        }
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "unknown"
                    }
                ]
            }
        ]
    },
    "references": {
        "reference_data": [
            {
                "url": "https://xenbits.xenproject.org/xsa/advisory-386.txt",
                "refsource": "MISC",
                "name": "https://xenbits.xenproject.org/xsa/advisory-386.txt"
            },
            {
                "refsource": "MLIST",
                "name": "[oss-security] 20211007 Xen Security Advisory 386 v2 (CVE-2021-28702) - PCI devices with RMRRs not deassigned correctly",
                "url": "http://www.openwall.com/lists/oss-security/2021/10/07/2"
            },
            {
                "refsource": "FEDORA",
                "name": "FEDORA-2021-80bbe7def0",
                "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TRAWV6PO2KUGVZTESERECOBUBZ6X45I7/"
            },
            {
                "refsource": "FEDORA",
                "name": "FEDORA-2021-0b7a484688",
                "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/FDPRMOBBLS74ONYP3IXZZXSTLKR7GRQB/"
            },
            {
                "refsource": "FEDORA",
                "name": "FEDORA-2021-829f5f2f43",
                "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2OIHEJ3R3EH5DYI2I5UMD2ULJ2ELA3EX/"
            },
            {
                "refsource": "DEBIAN",
                "name": "DSA-5017",
                "url": "https://www.debian.org/security/2021/dsa-5017"
            },
            {
                "refsource": "GENTOO",
                "name": "GLSA-202208-23",
                "url": "https://security.gentoo.org/glsa/202208-23"
            }
        ]
    },
    "workaround": {
        "workaround_data": {
            "description": {
                "description_data": [
                    {
                        "lang": "eng",
                        "value": "There is no mitigation (other than not passing through PCI devices\nwith RMRRs to guests)."
                    }
                ]
            }
        }
    }
}