Vulnerability-Lookup

BDU:2025-04679 (CVE-2021-47281)

Vulnerability from fstec – Published: 2025-04-17 – Updated: 2026-01-20 – View on bdu.fstec.ru Fixed

Title

Уязвимость функции snd_seq_timer_open() модуля sound/core/seq/seq_timer.c поддержки секвенсора ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

Summary

Уязвимость функции snd_seq_timer_open() модуля sound/core/seq/seq_timer.c поддержки секвенсора ядра операционной системы Linux связана с повторным использованием ранее освобожденной памяти. Эксплуатация уязвимости может позволить нарушителю вызвать отказ в обслуживании

Severity

6.0 (Medium) CVSS 2.0


                      
                        AV:L/AC:H/Au:S/C:C/I:C/A:C

7.0 (High) CVSS 3.0


                      
                        CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Class

Code vulnerability

Status

Confirmed by the vendor

Exploitation

Data structure manipulation

Incidents

Being clarified

Remediation

Software update

CWE

CWE-416 - Использование после освобождения

Aliases

CVE-2021-47281

References

14 references

URL
https://git.kernel.org/stable/c/536a7646c00a0f14fee49e5e313109e5da2f6031
https://git.kernel.org/stable/c/83e197a8414c0ba545e7e3916ce05f836f349273
https://git.kernel.org/stable/c/bd7d88b0874f82f7b29d1a53e574cedaf23166ba
https://www.cve.org/CVERecord?id=CVE-2021-47281
https://lore.kernel.org/linux-cve-announce/2024052153-CVE-2021-47281-d193@gregkh/
https://git.kernel.org/linus/83e197a8414c0ba545e7e3916ce05f836f349273
https://git.linuxtesting.ru/pub/scm/linux/kernel/git/lvc/linux-stable.git/commi…
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.44
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.11
https://security-tracker.debian.org/tracker/CVE-2021-47281
https://ubuntu.com/security/CVE-2021-47281
https://access.redhat.com/security/cve/CVE-2021-47281
https://cve.omp.ru/bb27514
https://cve.omp.ru/bb30515

Impacted products

5 products from 5 vendors

Vendors

Canonical Ltd., Red Hat, Inc., Сообщество свободного программного обеспечения, ООО "Открытая мобильная платформа"

Products

Ubuntu, Red Hat Enterprise Linux, Debian GNU/Linux, Linux, ОС Аврора (запись в едином реестре российских программ №1543)

Versions

16.04 LTS (Ubuntu), 18.04 LTS (Ubuntu), 8 (Red Hat Enterprise Linux), 20.04 LTS (Ubuntu), 11 (Debian GNU/Linux), 12 (Debian GNU/Linux), от 5.11 до 5.12.10 включительно (Linux), от 2.6.12 до 5.10.43 включительно (Linux), до 5.1.4 включительно (ОС Аврора), до 5.1.5 включительно (ОС Аврора)

Product types

Operating system

Platforms

Canonical Ltd. Ubuntu 16.04 LTS, Canonical Ltd. Ubuntu 18.04 LTS, Red Hat, Inc. Red Hat Enterprise Linux 8, Canonical Ltd. Ubuntu 20.04 LTS, Сообщество свободного программного обеспечения Debian GNU/Linux 11, Сообщество свободного программного обеспечения Debian GNU/Linux 12, Сообщество свободного программного обеспечения Linux от 5.11 до 5.12.10 включительно, Сообщество свободного программного обеспечения Linux от 2.6.12 до 5.10.43 включительно, ООО "Открытая мобильная платформа" ОС Аврора до 5.1.4 включительно (запись в едином реестре российских программ №1543), ООО "Открытая мобильная платформа" ОС Аврора до 5.1.5 включительно (запись в едином реестре российских программ №1543)

Mitigations

В условиях отсутствия обновлений безопасности от производителя рекомендуется придерживаться "Рекомендаций по безопасной настройке операционных систем LINUX", изложенных в методическом документе ФСТЭК России, утверждённом 25 декабря 2022 года. Использование рекомендаций: Для Linux: https://git.kernel.org/stable/c/536a7646c00a0f14fee49e5e313109e5da2f6031 https://git.kernel.org/stable/c/83e197a8414c0ba545e7e3916ce05f836f349273 https://git.kernel.org/stable/c/bd7d88b0874f82f7b29d1a53e574cedaf23166ba https://lore.kernel.org/linux-cve-announce/2024052153-CVE-2021-47281-d193@gregkh/ https://git.kernel.org/linus/83e197a8414c0ba545e7e3916ce05f836f349273 https://git.linuxtesting.ru/pub/scm/linux/kernel/git/lvc/linux-stable.git/commit/?h=v5.10.176-lvc1&id=bd7d88b0874f82f7b29d1a53e574cedaf23166ba https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.44 https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.11 Для Debian GNU/Linux: https://security-tracker.debian.org/tracker/CVE-2021-47281 Для Ubuntu: https://ubuntu.com/security/CVE-2021-47281 Для программных продуктов Red Hat Inc.: https://access.redhat.com/security/cve/CVE-2021-47281 Для ОС Аврора: https://cve.omp.ru/bb27514 Для ОС Аврора: https://cve.omp.ru/bb30515

JSON

To clipboard

{
  "CVSS 2.0": "AV:L/AC:H/Au:S/C:C/I:C/A:C",
  "CVSS 3.0": "AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "CVSS 4.0": null,
  "remediation_\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": null,
  "remediation_\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435": null,
  "\u0412\u0435\u043d\u0434\u043e\u0440 \u041f\u041e": "Canonical Ltd., Red Hat, Inc., \u0421\u043e\u043e\u0431\u0449\u0435\u0441\u0442\u0432\u043e \u0441\u0432\u043e\u0431\u043e\u0434\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f, \u041e\u041e\u041e \"\u041e\u0442\u043a\u0440\u044b\u0442\u0430\u044f \u043c\u043e\u0431\u0438\u043b\u044c\u043d\u0430\u044f \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u0430\"",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "16.04 LTS (Ubuntu), 18.04 LTS (Ubuntu), 8 (Red Hat Enterprise Linux), 20.04 LTS (Ubuntu), 11 (Debian GNU/Linux), 12 (Debian GNU/Linux), \u043e\u0442 5.11 \u0434\u043e 5.12.10 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 2.6.12 \u0434\u043e 5.10.43 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u0434\u043e 5.1.4 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (\u041e\u0421 \u0410\u0432\u0440\u043e\u0440\u0430), \u0434\u043e 5.1.5 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (\u041e\u0421 \u0410\u0432\u0440\u043e\u0440\u0430)",
  "\u0412\u043e\u0437\u043c\u043e\u0436\u043d\u044b\u0435 \u043c\u0435\u0440\u044b \u043f\u043e \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044e": "\u0412 \u0443\u0441\u043b\u043e\u0432\u0438\u044f\u0445 \u043e\u0442\u0441\u0443\u0442\u0441\u0442\u0432\u0438\u044f \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0439 \u0431\u0435\u0437\u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 \u043e\u0442 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u044f \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0443\u0435\u0442\u0441\u044f \u043f\u0440\u0438\u0434\u0435\u0440\u0436\u0438\u0432\u0430\u0442\u044c\u0441\u044f \"\u0420\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0439 \u043f\u043e \u0431\u0435\u0437\u043e\u043f\u0430\u0441\u043d\u043e\u0439 \u043d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0435 \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u044b\u0445 \u0441\u0438\u0441\u0442\u0435\u043c LINUX\", \u0438\u0437\u043b\u043e\u0436\u0435\u043d\u043d\u044b\u0445 \u0432 \u043c\u0435\u0442\u043e\u0434\u0438\u0447\u0435\u0441\u043a\u043e\u043c \u0434\u043e\u043a\u0443\u043c\u0435\u043d\u0442\u0435 \u0424\u0421\u0422\u042d\u041a \u0420\u043e\u0441\u0441\u0438\u0438, \u0443\u0442\u0432\u0435\u0440\u0436\u0434\u0451\u043d\u043d\u043e\u043c 25 \u0434\u0435\u043a\u0430\u0431\u0440\u044f 2022 \u0433\u043e\u0434\u0430.\n\n\u0418\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0439:\n\u0414\u043b\u044f Linux:\nhttps://git.kernel.org/stable/c/536a7646c00a0f14fee49e5e313109e5da2f6031\nhttps://git.kernel.org/stable/c/83e197a8414c0ba545e7e3916ce05f836f349273\nhttps://git.kernel.org/stable/c/bd7d88b0874f82f7b29d1a53e574cedaf23166ba\nhttps://lore.kernel.org/linux-cve-announce/2024052153-CVE-2021-47281-d193@gregkh/\nhttps://git.kernel.org/linus/83e197a8414c0ba545e7e3916ce05f836f349273\nhttps://git.linuxtesting.ru/pub/scm/linux/kernel/git/lvc/linux-stable.git/commit/?h=v5.10.176-lvc1\u0026id=bd7d88b0874f82f7b29d1a53e574cedaf23166ba\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.44\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.11\n\n\u0414\u043b\u044f Debian GNU/Linux:\nhttps://security-tracker.debian.org/tracker/CVE-2021-47281\n\n\u0414\u043b\u044f Ubuntu:\nhttps://ubuntu.com/security/CVE-2021-47281\n\n\u0414\u043b\u044f \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u044b\u0445 \u043f\u0440\u043e\u0434\u0443\u043a\u0442\u043e\u0432 Red Hat Inc.:\nhttps://access.redhat.com/security/cve/CVE-2021-47281\n\n\u0414\u043b\u044f \u041e\u0421 \u0410\u0432\u0440\u043e\u0440\u0430: https://cve.omp.ru/bb27514\n\n\u0414\u043b\u044f \u041e\u0421 \u0410\u0432\u0440\u043e\u0440\u0430: https://cve.omp.ru/bb30515",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "10.06.2021",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "20.01.2026",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "17.04.2025",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2025-04679",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440\u044b \u0434\u0440\u0443\u0433\u0438\u0445 \u0441\u0438\u0441\u0442\u0435\u043c \u043e\u043f\u0438\u0441\u0430\u043d\u0438\u0439 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "CVE-2021-47281",
  "\u0418\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f \u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0430",
  "\u041a\u043b\u0430\u0441\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043a\u043e\u0434\u0430",
  "\u041d\u0430\u0437\u0432\u0430\u043d\u0438\u0435 \u041f\u041e": "Ubuntu, Red Hat Enterprise Linux, Debian GNU/Linux, Linux, \u041e\u0421 \u0410\u0432\u0440\u043e\u0440\u0430 (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u21161543)",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u041e\u0421 \u0438 \u0442\u0438\u043f \u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u0439 \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u044b": "Canonical Ltd. Ubuntu 16.04 LTS , Canonical Ltd. Ubuntu 18.04 LTS , Red Hat, Inc. Red Hat Enterprise Linux 8 , Canonical Ltd. Ubuntu 20.04 LTS , \u0421\u043e\u043e\u0431\u0449\u0435\u0441\u0442\u0432\u043e \u0441\u0432\u043e\u0431\u043e\u0434\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f Debian GNU/Linux 11 , \u0421\u043e\u043e\u0431\u0449\u0435\u0441\u0442\u0432\u043e \u0441\u0432\u043e\u0431\u043e\u0434\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f Debian GNU/Linux 12 , \u0421\u043e\u043e\u0431\u0449\u0435\u0441\u0442\u0432\u043e \u0441\u0432\u043e\u0431\u043e\u0434\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f Linux \u043e\u0442 5.11 \u0434\u043e 5.12.10 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e , \u0421\u043e\u043e\u0431\u0449\u0435\u0441\u0442\u0432\u043e \u0441\u0432\u043e\u0431\u043e\u0434\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f Linux \u043e\u0442 2.6.12 \u0434\u043e 5.10.43 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e , \u041e\u041e\u041e \"\u041e\u0442\u043a\u0440\u044b\u0442\u0430\u044f \u043c\u043e\u0431\u0438\u043b\u044c\u043d\u0430\u044f \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u0430\" \u041e\u0421 \u0410\u0432\u0440\u043e\u0440\u0430 \u0434\u043e 5.1.4 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e  (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u21161543), \u041e\u041e\u041e \"\u041e\u0442\u043a\u0440\u044b\u0442\u0430\u044f \u043c\u043e\u0431\u0438\u043b\u044c\u043d\u0430\u044f \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u0430\" \u041e\u0421 \u0410\u0432\u0440\u043e\u0440\u0430 \u0434\u043e 5.1.5 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e  (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u21161543)",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0444\u0443\u043d\u043a\u0446\u0438\u0438 snd_seq_timer_open() \u043c\u043e\u0434\u0443\u043b\u044f sound/core/seq/seq_timer.c \u043f\u043e\u0434\u0434\u0435\u0440\u0436\u043a\u0438 \u0441\u0435\u043a\u0432\u0435\u043d\u0441\u043e\u0440\u0430 \u044f\u0434\u0440\u0430 \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u043e\u0439 \u0441\u0438\u0441\u0442\u0435\u043c\u044b Linux, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u043e\u0442\u043a\u0430\u0437 \u0432 \u043e\u0431\u0441\u043b\u0443\u0436\u0438\u0432\u0430\u043d\u0438\u0438",
  "\u041d\u0430\u043b\u0438\u0447\u0438\u0435 \u044d\u043a\u0441\u043f\u043b\u043e\u0439\u0442\u0430": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "\u0418\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u043f\u043e\u0441\u043b\u0435 \u043e\u0441\u0432\u043e\u0431\u043e\u0436\u0434\u0435\u043d\u0438\u044f (CWE-416)",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0444\u0443\u043d\u043a\u0446\u0438\u0438 snd_seq_timer_open() \u043c\u043e\u0434\u0443\u043b\u044f sound/core/seq/seq_timer.c \u043f\u043e\u0434\u0434\u0435\u0440\u0436\u043a\u0438 \u0441\u0435\u043a\u0432\u0435\u043d\u0441\u043e\u0440\u0430 \u044f\u0434\u0440\u0430 \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u043e\u0439 \u0441\u0438\u0441\u0442\u0435\u043c\u044b Linux \u0441\u0432\u044f\u0437\u0430\u043d\u0430 \u0441 \u043f\u043e\u0432\u0442\u043e\u0440\u043d\u044b\u043c \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435\u043c \u0440\u0430\u043d\u0435\u0435 \u043e\u0441\u0432\u043e\u0431\u043e\u0436\u0434\u0435\u043d\u043d\u043e\u0439 \u043f\u0430\u043c\u044f\u0442\u0438. \u042d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u043c\u043e\u0436\u0435\u0442 \u043f\u043e\u0437\u0432\u043e\u043b\u0438\u0442\u044c \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u043e\u0442\u043a\u0430\u0437 \u0432 \u043e\u0431\u0441\u043b\u0443\u0436\u0438\u0432\u0430\u043d\u0438\u0438",
  "\u041f\u043e\u0441\u043b\u0435\u0434\u0441\u0442\u0432\u0438\u044f \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": null,
  "\u041f\u0440\u043e\u0447\u0430\u044f \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f": null,
  "\u0421\u0432\u044f\u0437\u044c \u0441 \u0438\u043d\u0446\u0438\u0434\u0435\u043d\u0442\u0430\u043c\u0438 \u0418\u0411": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u0421\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d\u0430",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044f": "\u041e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438": "\u041c\u0430\u043d\u0438\u043f\u0443\u043b\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u0435 \u0441\u0442\u0440\u0443\u043a\u0442\u0443\u0440\u0430\u043c\u0438 \u0434\u0430\u043d\u043d\u044b\u0445",
  "\u0421\u0441\u044b\u043b\u043a\u0438 \u043d\u0430 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u0438": "https://git.kernel.org/stable/c/536a7646c00a0f14fee49e5e313109e5da2f6031\nhttps://git.kernel.org/stable/c/83e197a8414c0ba545e7e3916ce05f836f349273\nhttps://git.kernel.org/stable/c/bd7d88b0874f82f7b29d1a53e574cedaf23166ba\nhttps://www.cve.org/CVERecord?id=CVE-2021-47281\nhttps://lore.kernel.org/linux-cve-announce/2024052153-CVE-2021-47281-d193@gregkh/\nhttps://git.kernel.org/linus/83e197a8414c0ba545e7e3916ce05f836f349273\nhttps://git.linuxtesting.ru/pub/scm/linux/kernel/git/lvc/linux-stable.git/commit/?h=v5.10.176-lvc1\u0026id=bd7d88b0874f82f7b29d1a53e574cedaf23166ba\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.44\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.11\nhttps://security-tracker.debian.org/tracker/CVE-2021-47281\nhttps://ubuntu.com/security/CVE-2021-47281\nhttps://access.redhat.com/security/cve/CVE-2021-47281\nhttps://cve.omp.ru/bb27514\nhttps://cve.omp.ru/bb30515",
  "\u0421\u0442\u0430\u0442\u0443\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041f\u043e\u0434\u0442\u0432\u0435\u0440\u0436\u0434\u0435\u043d\u0430 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u0435\u043c",
  "\u0422\u0438\u043f \u041f\u041e": "\u041e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u0430\u044f \u0441\u0438\u0441\u0442\u0435\u043c\u0430",
  "\u0422\u0438\u043f \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "CWE-416",
  "\u0423\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0421\u0440\u0435\u0434\u043d\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 2.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 6)\n\u0412\u044b\u0441\u043e\u043a\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 3.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 7)"
}

CVE-2021-47281 (GCVE-0-2021-47281)

Vulnerability from cvelistv5 – Published: 2024-05-21 14:20 – Updated: 2026-08-05 08:47

Title

ALSA: seq: Fix race of snd_seq_timer_open()

Summary

In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Fix race of snd_seq_timer_open() The timer instance per queue is exclusive, and snd_seq_timer_open() should have managed the concurrent accesses. It looks as if it's checking the already existing timer instance at the beginning, but it's not right, because there is no protection, hence any later concurrent call of snd_seq_timer_open() may override the timer instance easily. This may result in UAF, as the leftover timer instance can keep running while the queue itself gets closed, as spotted by syzkaller recently. For avoiding the race, add a proper check at the assignment of tmr->timeri again, and return -EBUSY if it's been already registered.

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-05-23 21:20 UTC

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/bd7d88b0874f82f7b…
https://git.kernel.org/stable/c/536a7646c00a0f14f…
https://git.kernel.org/stable/c/83e197a8414c0ba54…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < bd7d88b0874f82f7b29d1a53e574cedaf23166ba (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 536a7646c00a0f14fee49e5e313109e5da2f6031 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 83e197a8414c0ba545e7e3916ce05f836f349273 (git)
Linux	Linux	Affected: 2.6.12 Unaffected: 0 , < 2.6.12 (semver) Unaffected: 5.10.44 , ≤ 5.10.* (semver) Unaffected: 5.12.11 , ≤ 5.12.* (semver) Unaffected: 5.13 , ≤ * (original_commit_for_fix)

Show details on NVD website

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2021-47281",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-05-23T21:20:28.570330Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2024-06-04T17:13:56.494Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      },
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T05:32:08.027Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/bd7d88b0874f82f7b29d1a53e574cedaf23166ba"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/536a7646c00a0f14fee49e5e313109e5da2f6031"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/83e197a8414c0ba545e7e3916ce05f836f349273"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "sound/core/seq/seq_timer.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "bd7d88b0874f82f7b29d1a53e574cedaf23166ba",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "536a7646c00a0f14fee49e5e313109e5da2f6031",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "83e197a8414c0ba545e7e3916ce05f836f349273",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "sound/core/seq/seq_timer.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.12"
            },
            {
              "lessThan": "2.6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.12.*",
              "status": "unaffected",
              "version": "5.12.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.13",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.44",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.12.11",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.13",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: seq: Fix race of snd_seq_timer_open()\n\nThe timer instance per queue is exclusive, and snd_seq_timer_open()\nshould have managed the concurrent accesses.  It looks as if it\u0027s\nchecking the already existing timer instance at the beginning, but\nit\u0027s not right, because there is no protection, hence any later\nconcurrent call of snd_seq_timer_open() may override the timer\ninstance easily.  This may result in UAF, as the leftover timer\ninstance can keep running while the queue itself gets closed, as\nspotted by syzkaller recently.\n\nFor avoiding the race, add a proper check at the assignment of\ntmr-\u003etimeri again, and return -EBUSY if it\u0027s been already registered."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The bug is reached through local ioctls on /dev/snd/seq (CREATE_QUEUE, SET_QUEUE_TIMER, SET_QUEUE_CLIENT, close), not via network or adjacent protocols.\nAC:L - The attacker controls both sides of the race by issuing concurrent sequencer ioctls/closes from multiple threads or processes on queues they create, as syzkaller did; success does not depend on victim state outside attacker influence.\nPR:L - Exploitation needs only the ability to open /dev/snd/seq as an unprivileged user (audio group, seat uaccess/ACL, or MIDI-capable app on phones); snd_seq_open imposes no capability checks.\nUI:N - The attacker triggers the race solely with their own open/ioctl/close operations; no action by another user is required.\nS:U - Impact stays within the host kernel authority (local privilege escalation / kernel memory corruption); it does not cross a VM, IOMMU, or other security boundary.\nC:H - The race orphans a running timer whose callback retains a pointer to a freed queue, producing a use-after-free that can be leveraged for arbitrary kernel memory disclosure.\nI:H - The same UAF on the queue object enables heap reuse and control-flow hijacking primitives, so integrity impact is high under kernel memory-corruption guidance.\nA:H - The UAF is observed as a kernel oops in softirq timer context (snd_seq_timer_interrupt), which can crash or hang the system."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T08:47:03.896Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/bd7d88b0874f82f7b29d1a53e574cedaf23166ba"
        },
        {
          "url": "https://git.kernel.org/stable/c/536a7646c00a0f14fee49e5e313109e5da2f6031"
        },
        {
          "url": "https://git.kernel.org/stable/c/83e197a8414c0ba545e7e3916ce05f836f349273"
        }
      ],
      "title": "ALSA: seq: Fix race of snd_seq_timer_open()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2021-47281",
    "datePublished": "2024-05-21T14:20:07.499Z",
    "dateReserved": "2024-05-21T13:27:52.128Z",
    "dateUpdated": "2026-08-05T08:47:03.896Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.