UBUNTU-CVE-2021-28689

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Source
https://ubuntu.com/security/CVE-2021-28689
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-28689.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2021-28689
Related
Published
2021-06-11T15:15:00Z
Modified
2024-10-15T14:08:05Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N CVSS Calculator
Summary
[none]
Details

x86: Speculative vulnerabilities with bare (non-shim) 32-bit PV guests 32-bit x86 PV guest kernels run in ring 1. At the time when Xen was developed, this area of the i386 architecture was rarely used, which is why Xen was able to use it to implement paravirtualisation, Xen's novel approach to virtualization. In AMD64, Xen had to use a different implementation approach, so Xen does not use ring 1 to support 64-bit guests. With the focus now being on 64-bit systems, and the availability of explicit hardware support for virtualization, fixing speculation issues in ring 1 is not a priority for processor companies. Indirect Branch Restricted Speculation (IBRS) is an architectural x86 extension put together to combat speculative execution sidechannel attacks, including Spectre v2. It was retrofitted in microcode to existing CPUs. For more details on Spectre v2, see: http://xenbits.xen.org/xsa/advisory-254.html However, IBRS does not architecturally protect ring 0 from predictions learnt in ring 1. For more details, see: https://software.intel.com/security-software-guidance/deep-dives/deep-dive-indirect-branch-restricted-speculation Similar situations may exist with other mitigations for other kinds of speculative execution attacks. The situation is quite likely to be similar for speculative execution attacks which have yet to be discovered, disclosed, or mitigated.

References

Affected packages

Ubuntu:Pro:16.04:LTS / xen

Package

Name
xen
Purl
pkg:deb/ubuntu/xen?arch=src?distro=esm-infra/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 

{
    "ubuntu_priority": "low"
}

Ubuntu:Pro:18.04:LTS / xen

Package

Name
xen
Purl
pkg:deb/ubuntu/xen?arch=src?distro=esm-infra/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 

{
    "ubuntu_priority": "low"
}

Ubuntu:20.04:LTS / xen

Package

Name
xen
Purl
pkg:deb/ubuntu/xen?arch=src?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 

{
    "ubuntu_priority": "low"
}

Ubuntu:22.04:LTS / xen

Package

Name
xen
Purl
pkg:deb/ubuntu/xen?arch=src?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 

{
    "ubuntu_priority": "low"
}

Ubuntu:24.10 / xen

Package

Name
xen
Purl
pkg:deb/ubuntu/xen?arch=src?distro=oracular

Affected ranges

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

Affected versions

4.*

4.17.3+10-g091466ba55-1.1ubuntu3

Ecosystem specific 

{
    "ubuntu_priority": "low"
}

Ubuntu:24.04:LTS / xen

Package

Name
xen
Purl
pkg:deb/ubuntu/xen?arch=src?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 

{
    "ubuntu_priority": "low"
}