Lucene search

[email protected]CVE-2021-28701

HistorySep 08, 2021 - 2:15 p.m.

CVE-2021-28701

2021-09-0814:15:08

CWE-362

[email protected]

web.nvd.nist.gov

104

cve-2021-28701

xenmapspace_grant_table

memory access

hypervisor

security vulnerability

4.4 Medium

CVSS2

Attack Vector

LOCAL

Attack Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

AV:L/AC:M/Au:N/C:P/I:P/A:P

7.8 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

7.5 High

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

14.2%

JSON

Another race in XENMAPSPACE_grant_table handling Guests are permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, are de-allocated when a guest switches (back) from v2 to v1. Freeing such pages requires that the hypervisor enforce that no parallel request can result in the addition of a mapping of such a page to a guest. That enforcement was missing, allowing guests to retain access to pages that were freed and perhaps re-used for other purposes. Unfortunately, when XSA-379 was being prepared, this similar issue was not noticed.

Affected configurations

NVD

Node

xenxenRange4.0.0≥

Node

debiandebian_linuxMatch11.0

Node

fedoraprojectfedoraMatch33

fedoraprojectfedoraMatch34

fedoraprojectfedoraMatch35

CPENameOperatorVersion
xen:xenxeneq*

CPE	Name	Operator	Version
xen:xen	xen	eq	*

CNA Affected

[
  {
    "product": "xen",
    "vendor": "Xen",
    "versions": [
      {
        "lessThan": "4.12",
        "status": "unknown",
        "version": "unspecified",
        "versionType": "custom"
      },
      {
        "lessThan": "unspecified",
        "status": "affected",
        "version": "4.15.x",
        "versionType": "custom"
      },
      {
        "lessThan": "unspecified",
        "status": "unaffected",
        "version": "next of xen-unstable",
        "versionType": "custom"
      }
    ]
  },
  {
    "product": "xen",
    "vendor": "Xen",
    "versions": [
      {
        "status": "affected",
        "version": "4.11.x"
      }
    ]
  },
  {
    "product": "xen",
    "vendor": "Xen",
    "versions": [
      {
        "lessThan": "4.12",
        "status": "unknown",
        "version": "unspecified",
        "versionType": "custom"
      },
      {
        "lessThan": "unspecified",
        "status": "affected",
        "version": "4.12.x",
        "versionType": "custom"
      },
      {
        "lessThan": "unspecified",
        "status": "unaffected",
        "version": "next of 4.14.x",
        "versionType": "custom"
      }
    ]
  }
]