cvelist/2021/28xxx/CVE-2021-28691.json

{
   "CVE_data_meta" : {
      "ASSIGNER" : "security@xenproject.org",
      "ID" : "CVE-2021-28691"
   },
   "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\n\nA malicious or buggy network PV frontend can force Linux netback to\ndisable the interface and terminate the receive kernel thread\nassociated with queue 0 in response to the frontend sending a\nmalformed packet.\n\nSuch kernel thread termination will lead to a use-after-free in Linux\nnetback when the backend is destroyed, as the kernel thread associated\nwith queue 0 will have already exited and thus the call to\nkthread_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"
         }
      ]
   },
   "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."
               }
            ]
         }
      }
   }
}