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Fencer Vulns
medium 4.9

CVE-2021-28700 json

xen/arm: No memory limit for dom0less domUs The dom0less feature allows an administrator to create multiple unprivileged domains directly f…

published 2021-08-27 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-15357

cvss
4.9
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.9%
EPSS 1.9% chance of exploitation in 30 days, percentile 79%
public exploits
0
none known

Summary

xen/arm: No memory limit for dom0less domUs The dom0less feature allows an administrator to create multiple unprivileged domains directly from Xen. Unfortunately, the memory limit from them is not set. This allow a domain to allocate memory beyond what an administrator originally configured.

Patch / fix

  • xen Debian 14, Debian 13, Debian 12 4.14.3-1

debian advisories DEBIAN-CVE-2021-28700

  • xen SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLES 15 SP1-BCL +6 more 4.12.4_12-3.52.1
  • xen SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 4.12.4_12-3.49.1
  • xen SLE Module for Server Applications 15 SP3, SLE Module for Basesystem 15 SP3 4.14.2_04-3.9.1
  • xen SLE Module for Server Applications 15 SP2, SLE Module for Basesystem 15 SP2, SLE Micro 5.0 4.13.3_02-3.34.1

suse advisories SUSE-SU-2021:2925-1SUSE-SU-2021:2924-1SUSE-SU-2021:2923-1SUSE-SU-2021:2922-1

  • xen openSUSE Leap 15.2 4.13.3_02-lp152.2.27.1
  • xen openSUSE Leap 15.3 4.14.2_04-3.9.1

opensuse advisories openSUSE-SU-2021:1236-1openSUSE-SU-2021:2923-1

  • xen Alpine 3.12, Alpine 3.11 4.13.3-r2
  • xen Alpine 3.13 4.14.2-r0
  • xen Alpine 3.24, Alpine 3.23, Alpine 3.22 +8 more 4.15.0-r2

alpine advisories ALPINE-CVE-2021-28700

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-28700 updated cvss 6.2

xen: malicious dom0less guest could drive Xen out of memory and leads to DoS

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.87% chance of exploitation in the next 30 days, higher than 79% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 4.9 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 6.8 AV:N/AC:L/Au:S/C:N/I:N/A:C

Affected products

  • Xen xen

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.