CVE-2021-20255

lowpriority · track · 22EPSS 0.004 · 35 %ileEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.41% (35th) EPSS

CVSS 2.1 · low

Is it mine?

12 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-27

A stack overflow via an infinite recursion vulnerability was found in the eepro100 i8255x device emulator of QEMU. This issue occurs while processing controller commands due to a DMA reentry issue. This flaw allows a guest user or process to consume CPU cycles or crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

cvss

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

5.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 2.1–5.5

v2.02.1lowAV:L/AC:L/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 3.9 · impact 2.9

v3.15.5mediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 3.6

v3.15.5mediumAV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.15.1mediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-674USprimaryCWE-674USCWE-835USCWE-835US

affected products (12)

Products and version ranges known to be affected.

n/a qemu≤ all versionsenisa_euvdEU
Fabrice Bellard QEMUall versionsfstec_bduRU
АО «Концерн ВНИИНС» ОС ОН «Стрелец»≤ 16.01.2023fstec_bduRU
АО «НППКТ» ОСОН ОСнова Оnyx≤ 2.5fstec_bduRU
АО «НТЦ ИТ РОСА» РОСА ХРОМ≤ 12.4fstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Special Edition≤ 4.7fstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Special Edition≤ 1.7fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 10fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 11fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 9fstec_bduRU
debian debian linux= 9.0nvdUScpe:2.3:o:debian:debian_linux:*:*:*:*:*:*:*:*
qemu qemuall versionsnvdUScpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd NVD CVE.org MITRE

published 2021-03-09modified 2026-06-17

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+723 more

references (29)

External citations — patches, advisories, analysis.

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