From fe44324c7a0ad8f7453d30df5666092fd33c4a61 Mon Sep 17 00:00:00 2001
From: Xen Project Security Team <security@xenproject.org>
Date: Wed, 6 Oct 2021 12:45:06 +0000
Subject: [PATCH] XSA-386 CVE-2021-28702

Xensec source data: xsa.git#xsa-386-v1
Xensec source infra: xsa.git#387bada8cfedfdb94deecebdec82b1f57b628e81
---
 2021/28xxx/CVE-2021-28702.json | 116 ++++++++++++++++++++++++++++-----
 1 file changed, 101 insertions(+), 15 deletions(-)

diff --git a/2021/28xxx/CVE-2021-28702.json b/2021/28xxx/CVE-2021-28702.json
index 7f93925b706..b7a2d701d38 100644
--- a/2021/28xxx/CVE-2021-28702.json
+++ b/2021/28xxx/CVE-2021-28702.json
@@ -1,18 +1,104 @@
 {
-    "data_type": "CVE",
-    "data_format": "MITRE",
-    "data_version": "4.0",
-    "CVE_data_meta": {
-        "ID": "CVE-2021-28702",
-        "ASSIGNER": "cve@mitre.org",
-        "STATE": "RESERVED"
-    },
-    "description": {
-        "description_data": [
+   "CVE_data_meta" : {
+      "ASSIGNER" : "security@xenproject.org",
+      "ID" : "CVE-2021-28702"
+   },
+   "affects" : {
+      "vendor" : {
+         "vendor_data" : [
             {
-                "lang": "eng",
-                "value": "** RESERVED ** This candidate has been reserved by an organization or individual that will use it when announcing a new security problem. When the candidate has been publicized, the details for this candidate will be provided."
+               "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"
             }
-        ]
-    }
-}
\ No newline at end of file
+         ]
+      }
+   },
+   "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\n\nCertain PCI devices in a system might be assigned Reserved Memory\nRegions (specified via Reserved Memory Region Reporting, \"RMRR\").\nThese are typically used for platform tasks such as legacy USB\nemulation.\n\nIf such a device is passed through to a guest, then on guest shutdown\nthe device is not properly deassigned.  The IOMMU configuration for\nthese devices which are not properly deassigned ends up pointing to a\nfreed data structure, including the IO Pagetables.\n\nSubsequent DMA or interrupts from the device will have unpredictable\nbehaviour, 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"
+         }
+      ]
+   },
+   "workaround" : {
+      "workaround_data" : {
+         "description" : {
+            "description_data" : [
+               {
+                  "lang" : "eng",
+                  "value" : "There is no mitigation (other than not passing through PCI devices\nwith RMRRs to guests)."
+               }
+            ]
+         }
+      }
+   }
+}