UBUNTU-CVE-2021-28703

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Source
https://ubuntu.com/security/CVE-2021-28703
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-28703.json
JSON Data
https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2021-28703
Upstream
Published
2021-12-07T12:15:00Z
Modified
2025-10-24T04:50:14Z
Severity
  • 7.0 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

grant table v2 status pages may remain accessible after de-allocation (take two) Guest get 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, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes. This bug was fortuitously fixed by code cleanup in Xen 4.14, and backported to security-supported Xen branches as a prerequisite of the fix for XSA-378.

References

Affected packages

Ubuntu:16.04:LTS

xen

Package

Name
xen
Purl
pkg:deb/ubuntu/xen@4.6.5-0ubuntu1.4?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*

4.5.1-0ubuntu1
4.5.1-0ubuntu2
4.6.0-1ubuntu1
4.6.0-1ubuntu2
4.6.0-1ubuntu4
4.6.0-1ubuntu4.1
4.6.0-1ubuntu4.2
4.6.0-1ubuntu4.3
4.6.5-0ubuntu1
4.6.5-0ubuntu1.1
4.6.5-0ubuntu1.2
4.6.5-0ubuntu1.4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libxen-4.6",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "libxen-dev",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "libxenstore3.0",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xen-hypervisor-4.4-amd64",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xen-hypervisor-4.4-arm64",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xen-hypervisor-4.4-armhf",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xen-hypervisor-4.5-amd64",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xen-hypervisor-4.5-arm64",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xen-hypervisor-4.5-armhf",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xen-hypervisor-4.6-amd64",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xen-hypervisor-4.6-arm64",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xen-hypervisor-4.6-armhf",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xen-system-amd64",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xen-system-arm64",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xen-system-armhf",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xen-utils-4.6",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xen-utils-common",
            "binary_version": "4.6.5-0ubuntu1.4"
        },
        {
            "binary_name": "xenstore-utils",
            "binary_version": "4.6.5-0ubuntu1.4"
        }
    ]
}

Ubuntu:18.04:LTS

xen

Package

Name
xen
Purl
pkg:deb/ubuntu/xen@4.9.2-0ubuntu1?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*

4.9.0-0ubuntu3
4.9.0-0ubuntu4
4.9.2-0ubuntu1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libxen-4.9",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "libxen-dev",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "libxenstore3.0",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-4.6-amd64",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-4.6-arm64",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-4.6-armhf",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-4.7-amd64",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-4.7-arm64",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-4.7-armhf",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-4.8-amd64",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-4.8-arm64",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-4.8-armhf",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-4.9-amd64",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-4.9-arm64",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-4.9-armhf",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-system-amd64",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-system-arm64",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-system-armhf",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-utils-4.9",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xen-utils-common",
            "binary_version": "4.9.2-0ubuntu1"
        },
        {
            "binary_name": "xenstore-utils",
            "binary_version": "4.9.2-0ubuntu1"
        }
    ]
}

Ubuntu:20.04:LTS

xen

Package

Name
xen
Purl
pkg:deb/ubuntu/xen@4.11.3+24-g14b62ab3e5-1ubuntu2.3?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*

4.9.2-0ubuntu2
4.9.2-0ubuntu6
4.9.2-0ubuntu7
4.11.3+24-g14b62ab3e5-1ubuntu1
4.11.3+24-g14b62ab3e5-1ubuntu2
4.11.3+24-g14b62ab3e5-1ubuntu2.2
4.11.3+24-g14b62ab3e5-1ubuntu2.3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libxen-dev",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "libxencall1",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "libxendevicemodel1",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "libxenevtchn1",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "libxenforeignmemory1",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "libxengnttab1",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "libxenmisc4.11",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "libxenstore3.0",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "libxentoolcore1",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "libxentoollog1",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "xen-hypervisor-4.11-amd64",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "xen-hypervisor-4.11-arm64",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "xen-hypervisor-4.11-armhf",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "xen-hypervisor-4.9-amd64",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "xen-hypervisor-4.9-arm64",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "xen-hypervisor-4.9-armhf",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "xen-hypervisor-common",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "xen-system-amd64",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "xen-system-arm64",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "xen-system-armhf",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "xen-utils-4.11",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "xen-utils-common",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        },
        {
            "binary_name": "xenstore-utils",
            "binary_version": "4.11.3+24-g14b62ab3e5-1ubuntu2.3"
        }
    ]
}

Ubuntu:22.04:LTS

xen

Package

Name
xen
Purl
pkg:deb/ubuntu/xen@4.16.0-1~ubuntu2.1?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*

4.11.4+24-gddaaccbbab-1ubuntu2
4.16.0-1~ubuntu2
4.16.0-1~ubuntu2.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libxen-dev",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "libxencall1",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "libxendevicemodel1",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "libxenevtchn1",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "libxenforeignmemory1",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "libxengnttab1",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "libxenhypfs1",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "libxenmisc4.16",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "libxenstore4",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "libxentoolcore1",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "libxentoollog1",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "xen-hypervisor-4.16-amd64",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "xen-hypervisor-4.16-arm64",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "xen-hypervisor-4.16-armhf",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "xen-hypervisor-common",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "xen-system-amd64",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "xen-system-arm64",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "xen-system-armhf",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "xen-utils-4.16",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "xen-utils-common",
            "binary_version": "4.16.0-1~ubuntu2.1"
        },
        {
            "binary_name": "xenstore-utils",
            "binary_version": "4.16.0-1~ubuntu2.1"
        }
    ]
}

Ubuntu:24.04:LTS

xen

Package

Name
xen
Purl
pkg:deb/ubuntu/xen@4.17.3+10-g091466ba55-1.1ubuntu3?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*

4.17.2-1
4.17.2+55-g0b56bed864-1
4.17.2+76-ge1f9cb16e2-1
4.17.2+76-ge1f9cb16e2-1ubuntu1
4.17.3+10-g091466ba55-1
4.17.3+10-g091466ba55-1.1ubuntu2
4.17.3+10-g091466ba55-1.1ubuntu3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libxen-dev",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "libxencall1t64",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "libxendevicemodel1t64",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "libxenevtchn1t64",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "libxenforeignmemory1t64",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "libxengnttab1t64",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "libxenhypfs1t64",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "libxenmisc4.17t64",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "libxenstore4t64",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "libxentoolcore1t64",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "libxentoollog1t64",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "xen-hypervisor-4.17-amd64",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "xen-hypervisor-4.17-arm64",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "xen-hypervisor-4.17-armhf",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "xen-hypervisor-common",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "xen-system-amd64",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "xen-system-arm64",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "xen-system-armhf",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "xen-utils-4.17",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "xen-utils-common",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        },
        {
            "binary_name": "xenstore-utils",
            "binary_version": "4.17.3+10-g091466ba55-1.1ubuntu3"
        }
    ]
}

Ubuntu:25.04

xen

Package

Name
xen
Purl
pkg:deb/ubuntu/xen@4.20.0-1ubuntu1?arch=source&distro=plucky

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*

4.17.3+10-g091466ba55-1.1ubuntu3
4.19.1-1ubuntu3
4.20.0-1ubuntu1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libxen-dev",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "libxencall1",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "libxendevicemodel1",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "libxenevtchn1",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "libxenforeignmemory1",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "libxengnttab1",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "libxenhypfs1",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "libxenmisc4.20",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "libxenstore4",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "libxentoolcore1",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "libxentoollog1",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-4.20-amd64",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-4.20-arm64",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "xen-hypervisor-common",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "xen-system-amd64",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "xen-system-arm64",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "xen-utils-4.20",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "xen-utils-common",
            "binary_version": "4.20.0-1ubuntu1"
        },
        {
            "binary_name": "xenstore-utils",
            "binary_version": "4.20.0-1ubuntu1"
        }
    ]
}

Ubuntu:25.10

xen

Package

Name
xen
Purl
pkg:deb/ubuntu/xen@4.20.0+68-g35cb38b222-1?arch=source&distro=questing

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*

4.20.0-1ubuntu1
4.20.0+68-g35cb38b222-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libxen-dev",
            "binary_version": "4.20.0+68-g35cb38b222-1"
        },
        {
            "binary_name": "libxencall1",
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