Lucene search

[email protected]CVE-2021-28698

HistoryAug 27, 2021 - 7:15 p.m.

CVE-2021-28698

2021-08-2719:15:07

CWE-835

[email protected]

web.nvd.nist.gov

109

cve

xen

resource use

grant table

cpu

hypervisor

4.9 Medium

CVSS2

Attack Vector

LOCAL

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

COMPLETE

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

5.5 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

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

6.3 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

14.2%

JSON

long running loops in grant table handling In order to properly monitor resource use, Xen maintains information on the grant mappings a domain may create to map grants offered by other domains. In the process of carrying out certain actions, Xen would iterate over all such entries, including ones which aren’t in use anymore and some which may have been created but never used. If the number of entries for a given domain is large enough, this iterating of the entire table may tie up a CPU for too long, starving other domains or causing issues in the hypervisor itself. Note that a domain may map its own grants, i.e. there is no need for multiple domains to be involved here. A pair of “cooperating” guests may, however, cause the effects to be more severe.

Affected configurations

NVD

Node

xenxenRange3.2.0≥

Node

fedoraprojectfedoraMatch33

fedoraprojectfedoraMatch34

fedoraprojectfedoraMatch35

Node

debiandebian_linuxMatch11.0

CPENameOperatorVersion
xen:xenxeneq*

CPE	Name	Operator	Version
xen:xen	xen	eq	*

CNA Affected

[
  {
    "product": "xen",
    "vendor": "Xen",
    "versions": [
      {
        "status": "affected",
        "version": "4.14.x"
      }
    ]
  },
  {
    "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": "4.13.x"
      }
    ]
  },
  {
    "product": "xen",
    "vendor": "Xen",
    "versions": [
      {
        "status": "affected",
        "version": "4.11.x"
      }
    ]
  },
  {
    "product": "xen",
    "vendor": "Xen",
    "versions": [
      {
        "status": "affected",
        "version": "4.12.x"
      }
    ]
  }
]