6.8

CVE-2021-28695: debian debian_linux

CVSS: 6.8v3.1MediumModified
AliasesALPINE-CVE-2021-28695UBUNTU-CVE-2021-28695DEBIAN-CVE-2021-28695
Published 27-08-2021Last modified 03-08-2024
Open JSON

Vulnerability summary

CVE-2021-28695 is a medium (CVSS 6.8) vulnerability in debian debian_linux. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 30.2% of scored vulnerabilities.

Overall risk
27/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.8/10
010
Medium · v3.1 (NVD)
EPSS score
0.38%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 11 · Related 10
DSA-4977-1OPENSUSE-SU-2021:1236-1OPENSUSE-SU-2021:2923-1SUSE-SU-2021:2922-1SUSE-SU-2021:2923-1SUSE-SU-2021:2924-1

Timeline

  1. 27-08-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

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).

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.38%

Chance of exploitation in the next 30 days

Percentile

30%

Versus all other CVEs

30-day change

0.00 pp

From 0.38% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.38%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Debian2 products
Alpine1 product
  • xen< 4.13.3-r2 | < 4.14.2-r0 | < 4.15.0-r2
Fedoraproject1 product
Ubuntu1 product
  • xenAll versions (No fix recorded)
Xen1 product
  • xen≥ 4.11.0, < 4.12.0 | xen-unstable | ≥ 4.12.0, < 4.13.0 | ≥ 4.14.0, < 4.15.0 | ≥ 4.15.0, < 4.16.0 | ≥ 4.13.0, < 4.14.0

5 vendors · 6 products

References

14 links
Show all 14 references