8.8

CVE-2021-28708: debian debian_linux

CVSS: 8.8v3.1HighModified
AliasesALPINE-CVE-2021-28708UBUNTU-CVE-2021-28708DEBIAN-CVE-2021-28708
Published 24-11-2021Last modified 18-11-2024
Open JSON

Vulnerability summary

CVE-2021-28708 is a high (CVSS 8.8) vulnerability in debian debian_linux. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 27.4% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.8/10
010
High · v3.1 (NVD)
EPSS score
0.35%
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-5017-1OPENSUSE-SU-2021:1543-1OPENSUSE-SU-2021:3968-1SUSE-SU-2021:3813-1SUSE-SU-2021:3842-1SUSE-SU-2021:3849-1

Timeline

  1. 24-11-2021
    PublishedVulnerability first disclosed.
  2. 18-11-2024
    Last modifiedVulnerability information updated.

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).

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.35%

Chance of exploitation in the next 30 days

Percentile

27%

Versus all other CVEs

30-day change

0.00 pp

From 0.35% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.35%

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≥ 4.7.0, < 4.13.4-r2 | ≥ 4.7.0, < 4.14.3-r2 | ≥ 4.7.0, < 4.15.1-r2
Fedoraproject1 product
Ubuntu1 product
  • xenAll versions (No fix recorded)
Xen1 product
  • xenxen-unstable | ≥ 4.12.x, < unspecified | ≥ 4.15.0, < 4.16.0 | ≥ 4.7.0, ≤ 4.15.1

5 vendors · 6 products

References

10 links