CVE-2021-28711

lowpriority · track · 26EPSS 0.003 · 26 %ileDERUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.33% (26th) EPSS
CVSS 2.1 · low
Is it mine?
28 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

Rogue backends can cause DoS of guests via high frequency events T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Xen offers the ability to run PV backends in regular unprivileged guests, typically referred to as "driver domains". Running PV backends in driver domains has one primary security advantage: if a driver domain gets compromised, it doesn't have the privileges to take over the system. However, a malicious driver domain could try to attack other guests via sending events at a high frequency leading to a Denial of Service in the guest due to trying to service interrupts for elongated amounts of time. There are three affected backends: * blkfront patch 1, CVE-2021-28711 * netfront patch 2, CVE-2021-28712 * hvc_xen (console) patch 3, CVE-2021-28713

01

cvss

Technical severity, 0–10. One row per scoring source.

6.5
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 2.1–6.5

v2.02.1lowAV:L/AC:L/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 3.9 · impact 2.9
v3.16.5mediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 2 · impact 4
v3.13.5lowAV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Lsecondary · FSTEC (BDU) RU
v3.16mediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
02

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-404US
03

affected products (28)

Products and version ranges known to be affected.

showing 20 of 28
04

advisories (1)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2023-0875Xen: Mehrere Schwachstellen ermöglichen Denial of ServiceDeutsch2021-12-20csaf · cert_bundDE

    Ein lokaler Angreifer kann mehrere Schwachstellen in Xen ausnutzen, um einen Denial of Service Angriff durchzuführen.

05

also known as (4)

Other names and identifiers for this entity.

06

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducert_bundNVDCVE.orgMITRE
published 2022-01-05modified 2026-06-17
07

references (32)

External citations — patches, advisories, analysis.

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