6.8
MEDIUM
CVE-2021-28695
AMD/Intel IOMMU x86 Firmware Untranslated Mapping Vulnerability
Description

IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Both AMD and Intel allow ACPI tables to specify regions of memory which should be left untranslated, which typically means these addresses should pass the translation phase unaltered. While these are typically device specific ACPI properties, they can also be specified to apply to a range of devices, or even all devices. On all systems with such regions Xen failed to prevent guests from undoing/replacing such mappings (CVE-2021-28694). On AMD systems, where a discontinuous range is specified by firmware, the supposedly-excluded middle range will also be identity-mapped (CVE-2021-28695). Further, on AMD systems, upon de-assigment of a physical device from a guest, the identity mappings would be left in place, allowing a guest continued access to ranges of memory which it shouldn't have access to anymore (CVE-2021-28696).

INFO

Published Date :

Aug. 27, 2021, 7:15 p.m.

Last Modified :

Nov. 7, 2023, 3:32 a.m.

Remotely Exploitable :

No

Impact Score :

5.9

Exploitability Score :

0.9
Public PoC/Exploit Available at Github

CVE-2021-28695 has a 1 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

Affected Products

The following products are affected by CVE-2021-28695 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).

Automatic monitor github cve using Github Actions

Python

Updated: 2 years, 11 months ago
0 stars 56 fork 56 watcher
Born at : April 7, 2021, 11:16 a.m. This repo has been linked 1007 different CVEs too.

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

The following list is the news that have been mention CVE-2021-28695 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-28695 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]

    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/LPRVHW4J4ZCPPOHZEWP5MOJT7XDGFFPJ/ [No types assigned]
    Added Reference Xen Project https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FZCNPSRPGFCQRYE2BI4D4Q4SCE56ANV2/ [No types assigned]
    Added Reference Xen Project https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2VQCFAPBNGBBAOMJZG6QBREOG5IIDZID/ [No types assigned]
    Removed Reference Xen Project https://lists.fedoraproject.org/archives/list/[email protected]/message/FZCNPSRPGFCQRYE2BI4D4Q4SCE56ANV2/
    Removed Reference Xen Project https://lists.fedoraproject.org/archives/list/[email protected]/message/LPRVHW4J4ZCPPOHZEWP5MOJT7XDGFFPJ/
    Removed Reference Xen Project https://lists.fedoraproject.org/archives/list/[email protected]/message/2VQCFAPBNGBBAOMJZG6QBREOG5IIDZID/
  • Modified Analysis by [email protected]

    Sep. 28, 2022

    Action Type Old Value New Value
    Changed Reference Type https://security.gentoo.org/glsa/202208-23 No Types Assigned https://security.gentoo.org/glsa/202208-23 Third Party Advisory
  • CVE Modified by [email protected]

    Aug. 15, 2022

    Action Type Old Value New Value
    Added Reference https://security.gentoo.org/glsa/202208-23 [No Types Assigned]
  • Modified Analysis by [email protected]

    Dec. 14, 2021

    Action Type Old Value New Value
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/2VQCFAPBNGBBAOMJZG6QBREOG5IIDZID/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/2VQCFAPBNGBBAOMJZG6QBREOG5IIDZID/ Mailing List, Third Party Advisory
    Changed Reference Type https://www.debian.org/security/2021/dsa-4977 No Types Assigned https://www.debian.org/security/2021/dsa-4977 Third Party Advisory
    Changed CPE Configuration OR *cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* *cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* OR *cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* *cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* *cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
    Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Sep. 24, 2021

    Action Type Old Value New Value
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/2VQCFAPBNGBBAOMJZG6QBREOG5IIDZID/ [No Types Assigned]
  • CVE Modified by [email protected]

    Sep. 21, 2021

    Action Type Old Value New Value
    Added Reference https://www.debian.org/security/2021/dsa-4977 [No Types Assigned]
  • Modified Analysis by [email protected]

    Sep. 14, 2021

    Action Type Old Value New Value
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/FZCNPSRPGFCQRYE2BI4D4Q4SCE56ANV2/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/FZCNPSRPGFCQRYE2BI4D4Q4SCE56ANV2/ Mailing List, Third Party Advisory
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/LPRVHW4J4ZCPPOHZEWP5MOJT7XDGFFPJ/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/LPRVHW4J4ZCPPOHZEWP5MOJT7XDGFFPJ/ Mailing List, Third Party Advisory
    Added CPE Configuration OR *cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* *cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Sep. 05, 2021

    Action Type Old Value New Value
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/FZCNPSRPGFCQRYE2BI4D4Q4SCE56ANV2/ [No Types Assigned]
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/LPRVHW4J4ZCPPOHZEWP5MOJT7XDGFFPJ/ [No Types Assigned]
  • Initial Analysis by [email protected]

    Sep. 01, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:L/AC:L/Au:N/C:P/I:P/A:P)
    Added CVSS V3.1 NIST AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Changed Reference Type http://www.openwall.com/lists/oss-security/2021/09/01/1 No Types Assigned http://www.openwall.com/lists/oss-security/2021/09/01/1 Mailing List, Third Party Advisory
    Changed Reference Type http://www.openwall.com/lists/oss-security/2021/09/01/5 No Types Assigned http://www.openwall.com/lists/oss-security/2021/09/01/5 Mailing List, Third Party Advisory
    Changed Reference Type http://www.openwall.com/lists/oss-security/2021/09/01/6 No Types Assigned http://www.openwall.com/lists/oss-security/2021/09/01/6 Mailing List, Third Party Advisory
    Changed Reference Type https://xenbits.xenproject.org/xsa/advisory-378.txt No Types Assigned https://xenbits.xenproject.org/xsa/advisory-378.txt Vendor Advisory
    Added CWE NIST NVD-CWE-noinfo
    Added CPE Configuration OR *cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Sep. 01, 2021

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2021/09/01/6 [No Types Assigned]
  • CVE Modified by [email protected]

    Sep. 01, 2021

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2021/09/01/5 [No Types Assigned]
  • CVE Modified by [email protected]

    Sep. 01, 2021

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2021/09/01/1 [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-2021-28695 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-2021-28695 weaknesses.

Exploit Prediction

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

0.12 }} 0.01%

score

0.45255

percentile

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