8.8
HIGH
CVE-2021-28707
Xen GFN PoD Alignment Vulnerability
Description

PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2).

INFO

Published Date :

Nov. 24, 2021, 1:15 a.m.

Last Modified :

Feb. 4, 2024, 8:15 a.m.

Remotely Exploitable :

No

Impact Score :

6.0

Exploitability Score :

2.0
Affected Products

The following products are affected by CVE-2021-28707 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Fedoraproject fedora
1 Debian debian_linux
1 Xen xen

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-28707 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-28707 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Feb. 04, 2024

    Action Type Old Value New Value
    Added Reference Xen Project https://security.gentoo.org/glsa/202402-07 [No types assigned]
  • CVE Modified by [email protected]

    Nov. 07, 2023

    Action Type Old Value New Value
    Added Reference Xen Project https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT/ [No types assigned]
    Added Reference Xen Project https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PXUI4VMD52CH3T7YXAG3J2JW7ZNN3SXF/ [No types assigned]
    Removed Reference Xen Project https://lists.fedoraproject.org/archives/list/[email protected]/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT/
    Removed Reference Xen Project https://lists.fedoraproject.org/archives/list/[email protected]/message/PXUI4VMD52CH3T7YXAG3J2JW7ZNN3SXF/
  • CWE Remap by [email protected]

    Jun. 28, 2022

    Action Type Old Value New Value
    Changed CWE CWE-77 NVD-CWE-noinfo
  • Modified Analysis by [email protected]

    Dec. 15, 2021

    Action Type Old Value New Value
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/PXUI4VMD52CH3T7YXAG3J2JW7ZNN3SXF/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/PXUI4VMD52CH3T7YXAG3J2JW7ZNN3SXF/ Mailing List, Third Party Advisory
    Changed Reference Type https://www.debian.org/security/2021/dsa-5017 No Types Assigned https://www.debian.org/security/2021/dsa-5017 Third Party Advisory
    Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
    Added CPE Configuration OR *cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* *cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Dec. 09, 2021

    Action Type Old Value New Value
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/PXUI4VMD52CH3T7YXAG3J2JW7ZNN3SXF/ [No Types Assigned]
  • CVE Modified by [email protected]

    Dec. 06, 2021

    Action Type Old Value New Value
    Added Reference https://www.debian.org/security/2021/dsa-5017 [No Types Assigned]
  • Initial Analysis by [email protected]

    Dec. 01, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:L/AC:M/Au:N/C:C/I:C/A:C)
    Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT/ Mailing List, Third Party Advisory
    Changed Reference Type https://xenbits.xenproject.org/xsa/advisory-388.txt No Types Assigned https://xenbits.xenproject.org/xsa/advisory-388.txt Patch, Vendor Advisory
    Added CWE NIST CWE-77
    Added CPE Configuration OR *cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:* versions from (including) 4.7.0 up to (including) 4.15.1
  • CVE Modified by [email protected]

    Dec. 01, 2021

    Action Type Old Value New Value
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT/ [No Types Assigned]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-28707 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-28707 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.06 }} 0.00%

score

0.25162

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability