{
    "CVE_data_meta": {
        "ASSIGNER": "security@xen.org",
        "ID": "CVE-2021-28691",
        "STATE": "PUBLIC"
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Linux",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "?<",
                                            "version_value": "4.12"
                                        },
                                        {
                                            "version_affected": ">=",
                                            "version_value": "5.5.0"
                                        },
                                        {
                                            "version_affected": "!>",
                                            "version_value": "5.12.2"
                                        }
                                    ]
                                }
                            }
                        ]
                    },
                    "vendor_name": "Linux"
                }
            ]
        }
    },
    "configuration": {
        "configuration_data": {
            "description": {
                "description_data": [
                    {
                        "lang": "eng",
                        "value": "Systems using Linux version 5.5 or newer are vulnerable."
                    }
                ]
            }
        }
    },
    "credit": {
        "credit_data": {
            "description": {
                "description_data": [
                    {
                        "lang": "eng",
                        "value": "This issue was discovered by Michael Brown of iPXE and diagnosed by\nOlivier Benjamin, Michael Kurth and Martin Mazein of AWS."
                    }
                ]
            }
        }
    },
    "data_format": "MITRE",
    "data_type": "CVE",
    "data_version": "4.0",
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "Guest triggered use-after-free in Linux xen-netback A malicious or buggy network PV frontend can force Linux netback to disable the interface and terminate the receive kernel thread associated with queue 0 in response to the frontend sending a malformed packet. Such kernel thread termination will lead to a use-after-free in Linux netback when the backend is destroyed, as the kernel thread associated with queue 0 will have already exited and thus the call to kthread_stop will be performed against a stale pointer."
            }
        ]
    },
    "impact": {
        "impact_data": {
            "description": {
                "description_data": [
                    {
                        "lang": "eng",
                        "value": "A malicious or buggy frontend driver can trigger a dom0 crash.\nPrivilege escalation and information leaks cannot be ruled out."
                    }
                ]
            }
        }
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "unknown"
                    }
                ]
            }
        ]
    },
    "references": {
        "reference_data": [
            {
                "url": "https://xenbits.xenproject.org/xsa/advisory-374.txt",
                "refsource": "MISC",
                "name": "https://xenbits.xenproject.org/xsa/advisory-374.txt"
            },
            {
                "refsource": "GENTOO",
                "name": "GLSA-202107-30",
                "url": "https://security.gentoo.org/glsa/202107-30"
            },
            {
                "refsource": "CONFIRM",
                "name": "https://security.netapp.com/advisory/ntap-20210805-0002/",
                "url": "https://security.netapp.com/advisory/ntap-20210805-0002/"
            }
        ]
    },
    "workaround": {
        "workaround_data": {
            "description": {
                "description_data": [
                    {
                        "lang": "eng",
                        "value": "On x86 running only HVM guests with emulated network cards will avoid the\nissue.  There's however no option in the upstream toolstack to offer only\nemulated network cards to guests."
                    }
                ]
            }
        }
    }
}