Vulnerability-Lookup

BDU:2025-07335 (CVE-2021-47245)

Vulnerability from fstec – Published: 2025-06-23 – Updated: 2025-06-23 – View on bdu.fstec.ru Fixed

Title

Уязвимость функции synproxy_parse_options() модуля net/netfilter/nf_synproxy_core.c компонента netfilter ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

Summary

Уязвимость функции synproxy_parse_options() модуля net/netfilter/nf_synproxy_core.c компонента netfilter ядра операционной системы Linux связана с чтением за границами буфера. Эксплуатация уязвимости может позволить нарушителю 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

Code vulnerability

Status

Confirmed by the vendor

Exploitation

Data structure manipulation

Incidents

Being clarified

Remediation

Software update

CWE

CWE-125 - Чтение за границами буфера

Aliases

CVE-2021-47245

References

19 references

URL
https://git.kernel.org/stable/c/9cdf299ba4e153b5e56187648420de22c6216f02
https://git.kernel.org/stable/c/6defc77d48eff74075b80ad5925061b2fc010d98
https://git.kernel.org/stable/c/5fc177ab759418c9537433e63301096e733fb915
https://git.kernel.org/stable/c/674b5f0c6a4fc5d3abce877048290cea6091fcb1
https://git.kernel.org/stable/c/f648089337cb8ed40b2bb96e244f72b9d97dc96b
https://git.kernel.org/stable/c/e1eb98cfeafdd85537e7e3cefe93ca9bfbcc3ea8
https://git.kernel.org/stable/c/7d9a9a1a88a3da574e019b4de756bc73337b3b0b
https://git.kernel.org/stable/c/576c1526b4d83c44ad7b673cb841f36cbc6cb6c4
https://www.cve.org/CVERecord?id=CVE-2021-47245
https://lore.kernel.org/linux-cve-announce/2024052143-CVE-2021-47245-13d9@gregkh/
https://git.kernel.org/linus/5fc177ab759418c9537433e63301096e733fb915
https://git.linuxtesting.ru/pub/scm/linux/kernel/git/lvc/linux-stable.git/commi…
https://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.4.274
https://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.274
https://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.238
https://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.196
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.128
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.46
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.13

Impacted products

1 product from 1 vendor

Vendors

Сообщество свободного программного обеспечения

Products

Linux

Versions

от 4.5 до 4.9.273 включительно (Linux), от 4.10 до 4.14.237 включительно (Linux), от 4.15 до 4.19.195 включительно (Linux), от 5.11 до 5.12.12 включительно (Linux), от 4.20 до 5.4.127 включительно (Linux), от 5.5 до 5.10.45 включительно (Linux), от 3.12 до 4.4.273 включительно (Linux)

Product types

Operating system

Platforms

Сообщество свободного программного обеспечения Linux от 4.5 до 4.9.273 включительно, Сообщество свободного программного обеспечения Linux от 4.10 до 4.14.237 включительно, Сообщество свободного программного обеспечения Linux от 4.15 до 4.19.195 включительно, Сообщество свободного программного обеспечения Linux от 5.11 до 5.12.12 включительно, Сообщество свободного программного обеспечения Linux от 4.20 до 5.4.127 включительно, Сообщество свободного программного обеспечения Linux от 5.5 до 5.10.45 включительно, Сообщество свободного программного обеспечения Linux от 3.12 до 4.4.273 включительно

Mitigations

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": "\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": "\u043e\u0442 4.5 \u0434\u043e 4.9.273 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 4.10 \u0434\u043e 4.14.237 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 4.15 \u0434\u043e 4.19.195 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 5.11 \u0434\u043e 5.12.12 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 4.20 \u0434\u043e 5.4.127 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 5.5 \u0434\u043e 5.10.45 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 3.12 \u0434\u043e 4.4.273 \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/9cdf299ba4e153b5e56187648420de22c6216f02\nhttps://git.kernel.org/stable/c/6defc77d48eff74075b80ad5925061b2fc010d98\nhttps://git.kernel.org/stable/c/5fc177ab759418c9537433e63301096e733fb915\nhttps://git.kernel.org/stable/c/674b5f0c6a4fc5d3abce877048290cea6091fcb1\nhttps://git.kernel.org/stable/c/f648089337cb8ed40b2bb96e244f72b9d97dc96b\nhttps://git.kernel.org/stable/c/e1eb98cfeafdd85537e7e3cefe93ca9bfbcc3ea8\nhttps://git.kernel.org/stable/c/7d9a9a1a88a3da574e019b4de756bc73337b3b0b\nhttps://git.kernel.org/stable/c/576c1526b4d83c44ad7b673cb841f36cbc6cb6c4\nhttps://lore.kernel.org/linux-cve-announce/2024052143-CVE-2021-47245-13d9@gregkh/\nhttps://git.kernel.org/linus/5fc177ab759418c9537433e63301096e733fb915\nhttps://git.linuxtesting.ru/pub/scm/linux/kernel/git/lvc/linux-stable.git/commit/?h=v5.10.176-lvc1\u0026id=9cdf299ba4e153b5e56187648420de22c6216f02\nhttps://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.4.274\nhttps://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.274\nhttps://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.238\nhttps://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.196\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.128\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.46\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.13",
  "\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": "23.06.2025",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "23.06.2025",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2025-07335",
  "\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-2021-47245",
  "\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": "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": "\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 4.5 \u0434\u043e 4.9.273 \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 4.10 \u0434\u043e 4.14.237 \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 4.15 \u0434\u043e 4.19.195 \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 5.11 \u0434\u043e 5.12.12 \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 4.20 \u0434\u043e 5.4.127 \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 \u0434\u043e 5.10.45 \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 3.12 \u0434\u043e 4.4.273 \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 synproxy_parse_options() \u043c\u043e\u0434\u0443\u043b\u044f net/netfilter/nf_synproxy_core.c \u043a\u043e\u043c\u043f\u043e\u043d\u0435\u043d\u0442\u0430 netfilter \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": "\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)",
  "\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 synproxy_parse_options() \u043c\u043e\u0434\u0443\u043b\u044f net/netfilter/nf_synproxy_core.c \u043a\u043e\u043c\u043f\u043e\u043d\u0435\u043d\u0442\u0430 netfilter \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 \u0447\u0442\u0435\u043d\u0438\u0435\u043c \u0437\u0430 \u0433\u0440\u0430\u043d\u0438\u0446\u0430\u043c\u0438 \u0431\u0443\u0444\u0435\u0440\u0430. \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",
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  "\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/9cdf299ba4e153b5e56187648420de22c6216f02\nhttps://git.kernel.org/stable/c/6defc77d48eff74075b80ad5925061b2fc010d98\nhttps://git.kernel.org/stable/c/5fc177ab759418c9537433e63301096e733fb915\nhttps://git.kernel.org/stable/c/674b5f0c6a4fc5d3abce877048290cea6091fcb1\nhttps://git.kernel.org/stable/c/f648089337cb8ed40b2bb96e244f72b9d97dc96b\nhttps://git.kernel.org/stable/c/e1eb98cfeafdd85537e7e3cefe93ca9bfbcc3ea8\nhttps://git.kernel.org/stable/c/7d9a9a1a88a3da574e019b4de756bc73337b3b0b\nhttps://git.kernel.org/stable/c/576c1526b4d83c44ad7b673cb841f36cbc6cb6c4\nhttps://www.cve.org/CVERecord?id=CVE-2021-47245\nhttps://lore.kernel.org/linux-cve-announce/2024052143-CVE-2021-47245-13d9@gregkh/\nhttps://git.kernel.org/linus/5fc177ab759418c9537433e63301096e733fb915\nhttps://git.linuxtesting.ru/pub/scm/linux/kernel/git/lvc/linux-stable.git/commit/?h=v5.10.176-lvc1\u0026id=9cdf299ba4e153b5e56187648420de22c6216f02\nhttps://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.4.274\nhttps://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.274\nhttps://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.238\nhttps://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.196\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.128\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.46\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.13",
  "\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",
  "\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-2021-47245 (GCVE-0-2021-47245)

Vulnerability from cvelistv5 – Published: 2024-05-21 14:19 – Updated: 2026-08-05 08:46

Title

netfilter: synproxy: Fix out of bounds when parsing TCP options

Summary

In the Linux kernel, the following vulnerability has been resolved: netfilter: synproxy: Fix out of bounds when parsing TCP options The TCP option parser in synproxy (synproxy_parse_options) could read one byte out of bounds. When the length is 1, the execution flow gets into the loop, reads one byte of the opcode, and if the opcode is neither TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds the length of 1. This fix is inspired by commit 9609dad263f8 ("ipv4: tcp_input: fix stack out of bounds when parsing TCP options."). v2 changes: Added an early return when length < 0 to avoid calling skb_header_pointer with negative length.

Severity

8.2 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-05-23 18:09 UTC

Assigner

Linux mitre root

References

8 references

URL	Tags
https://git.kernel.org/stable/c/e1eb98cfeafdd8553…
https://git.kernel.org/stable/c/576c1526b4d83c44a…
https://git.kernel.org/stable/c/674b5f0c6a4fc5d3a…
https://git.kernel.org/stable/c/7d9a9a1a88a3da574…
https://git.kernel.org/stable/c/6defc77d48eff7407…
https://git.kernel.org/stable/c/9cdf299ba4e153b5e…
https://git.kernel.org/stable/c/f648089337cb8ed40…
https://git.kernel.org/stable/c/5fc177ab759418c95…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 48b1de4c110a7afa4b85862f6c75af817db26fad , < e1eb98cfeafdd85537e7e3cefe93ca9bfbcc3ea8 (git) Affected: 48b1de4c110a7afa4b85862f6c75af817db26fad , < 576c1526b4d83c44ad7b673cb841f36cbc6cb6c4 (git) Affected: 48b1de4c110a7afa4b85862f6c75af817db26fad , < 674b5f0c6a4fc5d3abce877048290cea6091fcb1 (git) Affected: 48b1de4c110a7afa4b85862f6c75af817db26fad , < 7d9a9a1a88a3da574e019b4de756bc73337b3b0b (git) Affected: 48b1de4c110a7afa4b85862f6c75af817db26fad , < 6defc77d48eff74075b80ad5925061b2fc010d98 (git) Affected: 48b1de4c110a7afa4b85862f6c75af817db26fad , < 9cdf299ba4e153b5e56187648420de22c6216f02 (git) Affected: 48b1de4c110a7afa4b85862f6c75af817db26fad , < f648089337cb8ed40b2bb96e244f72b9d97dc96b (git) Affected: 48b1de4c110a7afa4b85862f6c75af817db26fad , < 5fc177ab759418c9537433e63301096e733fb915 (git)
Linux	Linux	Affected: 3.12 Unaffected: 0 , < 3.12 (semver) Unaffected: 4.4.274 , ≤ 4.4.* (semver) Unaffected: 4.9.274 , ≤ 4.9.* (semver) Unaffected: 4.14.238 , ≤ 4.14.* (semver) Unaffected: 4.19.196 , ≤ 4.19.* (semver) Unaffected: 5.4.128 , ≤ 5.4.* (semver) Unaffected: 5.10.46 , ≤ 5.10.* (semver) Unaffected: 5.12.13 , ≤ 5.12.* (semver) Unaffected: 5.13 , ≤ * (original_commit_for_fix)

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        {
          "cvssV3_1": {
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - synproxy_parse_options runs on received TCP packets in ipt_SYNPROXY/nft_synproxy and ipv4/ipv6_synproxy_hook; SYNPROXY is deployed on internet-facing hosts to mitigate SYN floods, so a remote peer triggers it with crafted TCP options.\nAC:L - The attacker fully controls the TCP option bytes and can reliably produce length==1 (e.g., NOPs plus a non-EOL/NOP kind) so the parser reads one byte past the end of the option data; no race or external condition is required.\nPR:N - Exploitation needs only the ability to send TCP segments to a host where SYNPROXY is enabled; no authentication or local account is required on that network path.\nUI:N - The vulnerable parser runs automatically on matching inbound TCP packets; no victim user action is required.\nS:U - Impact stays within the same kernel/host security authority; there is no VM, IOMMU, or other cross-boundary escape.\nC:L - The bug is a strictly one-byte out-of-bounds read (stack buf[40] or past copied option bytes) into a local opsize; per guidance that is a limited/bounded read (C:L), not an arbitrary read primitive.\nI:N - This is a read-only OOB; the byte is only used for length checks and is not written to attacker-controlled state, so there is no integrity or write primitive.\nA:H - Out-of-bounds kernel memory access can fault or otherwise disrupt the host (and is treated as DoS by multiple vendors); when uncertain, availability is scored High."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T08:46:56.392Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/e1eb98cfeafdd85537e7e3cefe93ca9bfbcc3ea8"
        },
        {
          "url": "https://git.kernel.org/stable/c/576c1526b4d83c44ad7b673cb841f36cbc6cb6c4"
        },
        {
          "url": "https://git.kernel.org/stable/c/674b5f0c6a4fc5d3abce877048290cea6091fcb1"
        },
        {
          "url": "https://git.kernel.org/stable/c/7d9a9a1a88a3da574e019b4de756bc73337b3b0b"
        },
        {
          "url": "https://git.kernel.org/stable/c/6defc77d48eff74075b80ad5925061b2fc010d98"
        },
        {
          "url": "https://git.kernel.org/stable/c/9cdf299ba4e153b5e56187648420de22c6216f02"
        },
        {
          "url": "https://git.kernel.org/stable/c/f648089337cb8ed40b2bb96e244f72b9d97dc96b"
        },
        {
          "url": "https://git.kernel.org/stable/c/5fc177ab759418c9537433e63301096e733fb915"
        }
      ],
      "title": "netfilter: synproxy: Fix out of bounds when parsing TCP options",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2021-47245",
    "datePublished": "2024-05-21T14:19:43.648Z",
    "dateReserved": "2024-04-10T18:59:19.533Z",
    "dateUpdated": "2026-08-05T08:46:56.392Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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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.

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.
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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.

Action not permitted

BDU:2025-07335 (CVE-2021-47245)

CVE-2021-47245 (GCVE-0-2021-47245)

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Sightings

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