Vulnerability-Lookup

BDU:2026-03971 (CVE-2020-36791)

Vulnerability from fstec – Published: 2026-03-26 – Updated: 2026-03-26 – View on bdu.fstec.ru Fixed

Title

Уязвимость функции tcindex_set_parms() модуля net/sched/cls_tcindex.c подсистемы управления трафиком net/sched ядра операционной системы Linux, позволяющая нарушителю получить доступ к защищаемой информации или вызвать отказ в обслуживании

Summary

Уязвимость функции tcindex_set_parms() модуля net/sched/cls_tcindex.c подсистемы управления трафиком net/sched ядра операционной системы Linux связана с распределением ресурсов без ограничений и регулирования. Эксплуатация уязвимости может позволить нарушителю получить доступ к защищаемой информации или вызвать отказ в обслуживании

Severity

6.2 (Medium) CVSS 2.0


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

7.1 (High) CVSS 3.1


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

Class

Multi-factor vulnerability

Status

Confirmed by the vendor

Exploitation

Data structure manipulation, Resource exhaustion

Incidents

Being clarified

Remediation

Software update

CWE

CWE-125 - Чтение за границами буфера
CWE-770 - Неограниченное распределение ресурсов или дросселирование

Aliases

CVE-2020-36791

References

17 references

URL
https://git.kernel.org/stable/c/557d015ffb27b672e24e6ad141fd887783871dc2
https://git.kernel.org/stable/c/bd3ee8fb6371b45c71c9345cc359b94da2ddefa9
https://git.kernel.org/stable/c/9f8b6c44be178c2498a00b270872a6e30e7c8266
https://syzkaller.appspot.com/bug?id=ea260693da894e7b078d18fca2c9c0a19b457534
https://git.kernel.org/stable/c/d6cdc5bb19b595486fb2e6661e5138d73a57f454
https://git.kernel.org/stable/c/d23faf32e577922b6da20bf3740625c1105381bf
https://blog.cdthoughts.ch/2021/03/16/syzbot-bug.html
https://git.kernel.org/stable/c/c4453d2833671e3a9f6bd52f0f581056c3736386
https://www.cve.org/CVERecord?id=CVE-2020-36791
https://git.kernel.org/linus/0d1c3530e1bd38382edef72591b78e877e0edcd3
https://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.4.218
https://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.218
https://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.175
https://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.114
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.29
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.14
https://ubuntu.com/security/CVE-2020-36791

Impacted products

2 products from 2 vendors

Vendors

Canonical Ltd., Сообщество свободного программного обеспечения

Products

Ubuntu, Linux

Versions

14.04 LTS (Ubuntu), 16.04 LTS (Ubuntu), 18.04 LTS (Ubuntu), от 4.4.214 до 4.4.217 включительно (Linux), от 4.9.214 до 4.9.217 включительно (Linux), от 4.14.171 до 4.14.174 включительно (Linux), от 4.19.103 до 4.19.113 включительно (Linux), от 5.4.19 до 5.4.28 включительно (Linux), от 5.5.3 до 5.5.13 включительно (Linux)

Product types

Operating system

Platforms

Canonical Ltd. Ubuntu 14.04 LTS, Canonical Ltd. Ubuntu 16.04 LTS, Canonical Ltd. Ubuntu 18.04 LTS, Сообщество свободного программного обеспечения Linux от 4.4.214 до 4.4.217 включительно, Сообщество свободного программного обеспечения Linux от 4.9.214 до 4.9.217 включительно, Сообщество свободного программного обеспечения Linux от 4.14.171 до 4.14.174 включительно, Сообщество свободного программного обеспечения Linux от 4.19.103 до 4.19.113 включительно, Сообщество свободного программного обеспечения Linux от 5.4.19 до 5.4.28 включительно, Сообщество свободного программного обеспечения Linux от 5.5.3 до 5.5.13 включительно

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/557d015ffb27b672e24e6ad141fd887783871dc2 https://git.kernel.org/stable/c/bd3ee8fb6371b45c71c9345cc359b94da2ddefa9 https://git.kernel.org/stable/c/9f8b6c44be178c2498a00b270872a6e30e7c8266 https://syzkaller.appspot.com/bug?id=ea260693da894e7b078d18fca2c9c0a19b457534 https://git.kernel.org/stable/c/d6cdc5bb19b595486fb2e6661e5138d73a57f454 https://git.kernel.org/stable/c/d23faf32e577922b6da20bf3740625c1105381bf Для программных продуктов Ubuntu: https://ubuntu.com/security/CVE-2020-36791

JSON

To clipboard

{
  "CVSS 2.0": "AV:L/AC:L/Au:S/C:C/I:N/A:C",
  "CVSS 3.0": "AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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., \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",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "14.04 LTS (Ubuntu), 16.04 LTS (Ubuntu), 18.04 LTS (Ubuntu), \u043e\u0442 4.4.214 \u0434\u043e 4.4.217 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 4.9.214 \u0434\u043e 4.9.217 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 4.14.171 \u0434\u043e 4.14.174 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 4.19.103 \u0434\u043e 4.19.113 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 5.4.19 \u0434\u043e 5.4.28 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 5.5.3 \u0434\u043e 5.5.13 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux)",
  "\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/557d015ffb27b672e24e6ad141fd887783871dc2\nhttps://git.kernel.org/stable/c/bd3ee8fb6371b45c71c9345cc359b94da2ddefa9\nhttps://git.kernel.org/stable/c/9f8b6c44be178c2498a00b270872a6e30e7c8266\nhttps://syzkaller.appspot.com/bug?id=ea260693da894e7b078d18fca2c9c0a19b457534\nhttps://git.kernel.org/stable/c/d6cdc5bb19b595486fb2e6661e5138d73a57f454\nhttps://git.kernel.org/stable/c/d23faf32e577922b6da20bf3740625c1105381bf\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 Ubuntu:\nhttps://ubuntu.com/security/CVE-2020-36791",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "14.03.2020",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "26.03.2026",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "26.03.2026",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2026-03971",
  "\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-2020-36791",
  "\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 \u043c\u043d\u043e\u0433\u043e\u0444\u0430\u043a\u0442\u043e\u0440\u043d\u0430\u044f",
  "\u041d\u0430\u0437\u0432\u0430\u043d\u0438\u0435 \u041f\u041e": "Ubuntu, Linux",
  "\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 14.04 LTS , Canonical Ltd. Ubuntu 16.04 LTS , Canonical Ltd. Ubuntu 18.04 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 Linux \u043e\u0442 4.4.214 \u0434\u043e 4.4.217 \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 4.9.214 \u0434\u043e 4.9.217 \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 4.14.171 \u0434\u043e 4.14.174 \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 4.19.103 \u0434\u043e 4.19.113 \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 5.4.19 \u0434\u043e 5.4.28 \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 5.5.3 \u0434\u043e 5.5.13 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e ",
  "\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 tcindex_set_parms() \u043c\u043e\u0434\u0443\u043b\u044f net/sched/cls_tcindex.c \u043f\u043e\u0434\u0441\u0438\u0441\u0442\u0435\u043c\u044b \u0443\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u044f \u0442\u0440\u0430\u0444\u0438\u043a\u043e\u043c net/sched \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 \u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c \u0434\u043e\u0441\u0442\u0443\u043f \u043a \u0437\u0430\u0449\u0438\u0449\u0430\u0435\u043c\u043e\u0439 \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u0438 \u0438\u043b\u0438 \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": "\u0427\u0442\u0435\u043d\u0438\u0435 \u0437\u0430 \u0433\u0440\u0430\u043d\u0438\u0446\u0430\u043c\u0438 \u0431\u0443\u0444\u0435\u0440\u0430 (CWE-125), \u041d\u0435\u043e\u0433\u0440\u0430\u043d\u0438\u0447\u0435\u043d\u043d\u043e\u0435 \u0440\u0430\u0441\u043f\u0440\u0435\u0434\u0435\u043b\u0435\u043d\u0438\u0435 \u0440\u0435\u0441\u0443\u0440\u0441\u043e\u0432 \u0438\u043b\u0438 \u0434\u0440\u043e\u0441\u0441\u0435\u043b\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u0435 (CWE-770)",
  "\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 tcindex_set_parms() \u043c\u043e\u0434\u0443\u043b\u044f net/sched/cls_tcindex.c \u043f\u043e\u0434\u0441\u0438\u0441\u0442\u0435\u043c\u044b \u0443\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u044f \u0442\u0440\u0430\u0444\u0438\u043a\u043e\u043c net/sched \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 \u0440\u0430\u0441\u043f\u0440\u0435\u0434\u0435\u043b\u0435\u043d\u0438\u0435\u043c \u0440\u0435\u0441\u0443\u0440\u0441\u043e\u0432 \u0431\u0435\u0437 \u043e\u0433\u0440\u0430\u043d\u0438\u0447\u0435\u043d\u0438\u0439 \u0438 \u0440\u0435\u0433\u0443\u043b\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u044f. \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 \u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c \u0434\u043e\u0441\u0442\u0443\u043f \u043a \u0437\u0430\u0449\u0438\u0449\u0430\u0435\u043c\u043e\u0439 \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u0438 \u0438\u043b\u0438 \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, \u0418\u0441\u0447\u0435\u0440\u043f\u0430\u043d\u0438\u0435 \u0440\u0435\u0441\u0443\u0440\u0441\u043e\u0432",
  "\u0421\u0441\u044b\u043b\u043a\u0438 \u043d\u0430 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u0438": "https://git.kernel.org/stable/c/557d015ffb27b672e24e6ad141fd887783871dc2\nhttps://git.kernel.org/stable/c/bd3ee8fb6371b45c71c9345cc359b94da2ddefa9\nhttps://git.kernel.org/stable/c/9f8b6c44be178c2498a00b270872a6e30e7c8266\nhttps://syzkaller.appspot.com/bug?id=ea260693da894e7b078d18fca2c9c0a19b457534\nhttps://git.kernel.org/stable/c/d6cdc5bb19b595486fb2e6661e5138d73a57f454\nhttps://git.kernel.org/stable/c/d23faf32e577922b6da20bf3740625c1105381bf\nhttps://blog.cdthoughts.ch/2021/03/16/syzbot-bug.html\nhttps://git.kernel.org/stable/c/c4453d2833671e3a9f6bd52f0f581056c3736386\nhttps://www.cve.org/CVERecord?id=CVE-2020-36791\nhttps://git.kernel.org/linus/0d1c3530e1bd38382edef72591b78e877e0edcd3\nhttps://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.4.218\nhttps://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.218\nhttps://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.175\nhttps://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.114\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.29\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.14\nhttps://ubuntu.com/security/CVE-2020-36791",
  "\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-125, CWE-770",
  "\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 6,2)\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 3.1 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 7,1)"
}

CVE-2020-36791 (GCVE-0-2020-36791)

Vulnerability from cvelistv5 – Published: 2025-05-07 13:17 – Updated: 2026-08-05 08:44

Title

net_sched: keep alloc_hash updated after hash allocation

Summary

In the Linux kernel, the following vulnerability has been resolved: net_sched: keep alloc_hash updated after hash allocation In commit 599be01ee567 ("net_sched: fix an OOB access in cls_tcindex") I moved cp->hash calculation before the first tcindex_alloc_perfect_hash(), but cp->alloc_hash is left untouched. This difference could lead to another out of bound access. cp->alloc_hash should always be the size allocated, we should update it after this tcindex_alloc_perfect_hash().

Severity

7.8 (High)


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

Assigner

Linux mitre root

References

9 references

URL	Tags
https://git.kernel.org/stable/c/d6cdc5bb19b595486…
https://git.kernel.org/stable/c/c4453d2833671e3a9…
https://git.kernel.org/stable/c/9f8b6c44be178c249…
https://git.kernel.org/stable/c/557d015ffb27b672e…
https://git.kernel.org/stable/c/d23faf32e577922b6…
https://git.kernel.org/stable/c/bd3ee8fb6371b45c7…
https://git.kernel.org/stable/c/0d1c3530e1bd38382…
https://syzkaller.appspot.com/bug?id=ea260693da89…
https://blog.cdthoughts.ch/2021/03/16/syzbot-bug.html

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 73c29d2f6f8ae731b1e09051b69ed3ba2319482b , < d6cdc5bb19b595486fb2e6661e5138d73a57f454 (git) Affected: b974ac51f5834a729de252fc5c1c9de9efd79b45 , < c4453d2833671e3a9f6bd52f0f581056c3736386 (git) Affected: 6cb448ee493c8a514c9afa0c346f3f5b3227de85 , < 9f8b6c44be178c2498a00b270872a6e30e7c8266 (git) Affected: 478c4b2ffd44e5186c7e22ae7c38a86a5b9cfde5 , < 557d015ffb27b672e24e6ad141fd887783871dc2 (git) Affected: dd8142a6fa5270783d415292ec8169f4ea2a5468 , < d23faf32e577922b6da20bf3740625c1105381bf (git) Affected: 2c66ff8d08f81bcf8e8cb22e31e39c051b15336a , < bd3ee8fb6371b45c71c9345cc359b94da2ddefa9 (git) Affected: 599be01ee567b61f4471ee8078870847d0a11e8e , < 0d1c3530e1bd38382edef72591b78e877e0edcd3 (git)
Linux	Linux	Affected: 4.4.214 , < 4.4.218 (semver) Affected: 4.9.214 , < 4.9.218 (semver) Affected: 4.14.171 , < 4.14.175 (semver) Affected: 4.19.103 , < 4.19.114 (semver) Affected: 5.4.19 , < 5.4.29 (semver) Affected: 5.5.3 , < 5.5.14 (semver)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sched/cls_tcindex.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "d6cdc5bb19b595486fb2e6661e5138d73a57f454",
              "status": "affected",
              "version": "73c29d2f6f8ae731b1e09051b69ed3ba2319482b",
              "versionType": "git"
            },
            {
              "lessThan": "c4453d2833671e3a9f6bd52f0f581056c3736386",
              "status": "affected",
              "version": "b974ac51f5834a729de252fc5c1c9de9efd79b45",
              "versionType": "git"
            },
            {
              "lessThan": "9f8b6c44be178c2498a00b270872a6e30e7c8266",
              "status": "affected",
              "version": "6cb448ee493c8a514c9afa0c346f3f5b3227de85",
              "versionType": "git"
            },
            {
              "lessThan": "557d015ffb27b672e24e6ad141fd887783871dc2",
              "status": "affected",
              "version": "478c4b2ffd44e5186c7e22ae7c38a86a5b9cfde5",
              "versionType": "git"
            },
            {
              "lessThan": "d23faf32e577922b6da20bf3740625c1105381bf",
              "status": "affected",
              "version": "dd8142a6fa5270783d415292ec8169f4ea2a5468",
              "versionType": "git"
            },
            {
              "lessThan": "bd3ee8fb6371b45c71c9345cc359b94da2ddefa9",
              "status": "affected",
              "version": "2c66ff8d08f81bcf8e8cb22e31e39c051b15336a",
              "versionType": "git"
            },
            {
              "lessThan": "0d1c3530e1bd38382edef72591b78e877e0edcd3",
              "status": "affected",
              "version": "599be01ee567b61f4471ee8078870847d0a11e8e",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sched/cls_tcindex.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4.4.218",
              "status": "affected",
              "version": "4.4.214",
              "versionType": "semver"
            },
            {
              "lessThan": "4.9.218",
              "status": "affected",
              "version": "4.9.214",
              "versionType": "semver"
            },
            {
              "lessThan": "4.14.175",
              "status": "affected",
              "version": "4.14.171",
              "versionType": "semver"
            },
            {
              "lessThan": "4.19.114",
              "status": "affected",
              "version": "4.19.103",
              "versionType": "semver"
            },
            {
              "lessThan": "5.4.29",
              "status": "affected",
              "version": "5.4.19",
              "versionType": "semver"
            },
            {
              "lessThan": "5.5.14",
              "status": "affected",
              "version": "5.5.3",
              "versionType": "semver"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.4.218",
                  "versionStartIncluding": "4.4.214",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.9.218",
                  "versionStartIncluding": "4.9.214",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.14.175",
                  "versionStartIncluding": "4.14.171",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.19.114",
                  "versionStartIncluding": "4.19.103",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.4.29",
                  "versionStartIncluding": "5.4.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.5.14",
                  "versionStartIncluding": "5.5.3",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet_sched: keep alloc_hash updated after hash allocation\n\nIn commit 599be01ee567 (\"net_sched: fix an OOB access in cls_tcindex\")\nI moved cp-\u003ehash calculation before the first\ntcindex_alloc_perfect_hash(), but cp-\u003ealloc_hash is left untouched.\nThis difference could lead to another out of bound access.\n\ncp-\u003ealloc_hash should always be the size allocated, we should\nupdate it after this tcindex_alloc_perfect_hash()."
        }
      ],
      "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 triggered through the tc filter netlink configuration path (RTM_NEWTFILTER \u2192 tc_new_tfilter \u2192 tcindex_change \u2192 tcindex_set_parms), not by processing network packets. Exploitation requires local netlink/syscall access to configure cls_tcindex.\nAC:L - An attacker fully controls both the old and new hash sizes and the filter handle via netlink attributes, so shrinking a perfect hash while using a handle past the newly allocated size reliably produces the OOB access with no race or external conditions.\nPR:L - tc_new_tfilter requires CAP_NET_ADMIN checked with netlink_ns_capable against the network namespace\u0027s user_ns, which an unprivileged user can obtain via user namespaces (unshare -Urn) without real root in the init namespace.\nUI:N - The attacker creates and modifies their own tcindex filters in a network namespace they control; no victim action is required.\nS:U - Impact is confined to the host kernel privilege boundary (local memory corruption / privilege escalation) and does not cross VM, IOMMU, or other distinct security authorities.\nC:H - Stale alloc_hash allows OOB reads through tcindex_get/tcindex_lookup (perfect + handle beyond the allocated array), and the heap OOB can be leveraged for arbitrary kernel memory disclosure.\nI:H - tcindex_set_parms does r = cp-\u003eperfect + handle then writes result/exts into that slot; with handle past the newly allocated hash this is a controlled heap out-of-bounds write enabling memory corruption and control-flow hijacking.\nA:H - The out-of-bounds access was caught by syzbot as a kernel memory-safety failure and can produce oops/panic or heap corruption leading to a crash even without full exploitation."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T08:44:33.087Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/d6cdc5bb19b595486fb2e6661e5138d73a57f454"
        },
        {
          "url": "https://git.kernel.org/stable/c/c4453d2833671e3a9f6bd52f0f581056c3736386"
        },
        {
          "url": "https://git.kernel.org/stable/c/9f8b6c44be178c2498a00b270872a6e30e7c8266"
        },
        {
          "url": "https://git.kernel.org/stable/c/557d015ffb27b672e24e6ad141fd887783871dc2"
        },
        {
          "url": "https://git.kernel.org/stable/c/d23faf32e577922b6da20bf3740625c1105381bf"
        },
        {
          "url": "https://git.kernel.org/stable/c/bd3ee8fb6371b45c71c9345cc359b94da2ddefa9"
        },
        {
          "url": "https://git.kernel.org/stable/c/0d1c3530e1bd38382edef72591b78e877e0edcd3"
        },
        {
          "url": "https://syzkaller.appspot.com/bug?id=ea260693da894e7b078d18fca2c9c0a19b457534"
        },
        {
          "url": "https://blog.cdthoughts.ch/2021/03/16/syzbot-bug.html"
        }
      ],
      "title": "net_sched: keep alloc_hash updated after hash allocation",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2020-36791",
    "datePublished": "2025-05-07T13:17:33.882Z",
    "dateReserved": "2024-02-26T17:07:27.435Z",
    "dateUpdated": "2026-08-05T08:44:33.087Z",
    "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.