Vulnerability-Lookup

BDU:2022-05987 (CVE-2021-27853)

Vulnerability from fstec – Published: 2022-09-28 – Updated: 2024-09-13 – View on bdu.fstec.ru Exploit publicly available Fixed

Title

Уязвимость реализации протокола инкапсуляции Ethernet, связанная с возможностью объединения заголовков, позволяющая нарушителю вызвать отказ в обслуживании или реализовать атаку «человек посередине» (MITM)

Summary

Уязвимость реализации протокола инкапсуляции Ethernet связана с возможностью объединения заголовков. Эксплуатация уязвимости может позволить нарушителю, действующему удалённо, вызвать отказ в обслуживании или реализовать атаку «человек посередине» (MITM)

Severity

3.3 (Low) CVSS 2.0


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

4.7 (Medium) CVSS 3.0


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

Class

Code vulnerability

Status

Confirmed by the vendor

Exploitation

Authentication bypass

Incidents

Being clarified

Remediation

Software update

CWE

CWE-290 - Обход аутентификации посредством спуфинга

Aliases

CVE-2021-27853

References

6 references

URL
https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/
https://standards.ieee.org/ieee/802.1Q/10323/
https://standards.ieee.org/ieee/802.2/1048/
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-…
https://kb.cert.org/vuls/id/855201
https://blog.champtar.fr/VLAN0_LLC_SNAP/

Impacted products

18 products from 3 vendors

Vendors

Cisco Systems, Inc., Juniper Networks Inc.

Products

NX-OS, Cisco IOS, Cisco IOS XE, MS390, MS210, MS225, MS250, MS350, MS355, MS410, MS420, MS425, MS450, Business 250 Series Smart Switches, Business 350 Series Managed Switches, Cisco 350X Series Managed Switches, Cisco Small Business 550X Series, JunOS

Versions

- (NX-OS), - (Cisco IOS), - (Cisco IOS XE), - (MS390), - (MS210), - (MS225), - (MS250), - (MS350), - (MS355), - (MS410), - (MS420), - (MS425), - (MS450), - (Business 250 Series Smart Switches), - (Business 350 Series Managed Switches), - (Cisco 350X Series Managed Switches), - (Cisco Small Business 550X Series), до 21.2R3-S3 (JunOS), до 21.3R3-S1 (JunOS), до 21.4R2-S2 (JunOS), до 21.4R3 (JunOS), до 22.1R1-S2 (JunOS), до 22.1R2 (JunOS), до 22.1R3 (JunOS), до 22.2R2 (JunOS), до 22.3R1 (JunOS), до 22.1R3-EVO (JunOS), до 22.2R2-EVO (JunOS), до 22.3R1-EVO (JunOS), до 22.4R1-EVO (JunOS)

Product types

Operating system, Network appliance software, Network device, Network software, Appliance software

Platforms

Cisco Systems, Inc. NX-OS - Nexus 9000 Series in Standalone NX-OS Mode, Inc. Cisco IOS - Cisco Catalyst 6500, Inc. Cisco IOS - Cisco Catalyst 6800 Series, Inc. Cisco IOS - Catalyst Digital Building Series Switches, Inc. Cisco IOS - Industrial Ethernet Switches, Inc. Cisco IOS - Micro Switches, Inc. Cisco IOS XE - Cisco Catalyst 4500 Series, Inc. Cisco IOS XE - IOS XE Switches, Inc. NX-OS - Cisco Nexus 3000 Series, Inc. NX-OS - Cisco Nexus 5500 Platform Switches, Inc. NX-OS - Cisco Nexus 5600 Platform Switches, Inc. NX-OS - Cisco Nexus 6000 Series Switches, Inc. NX-OS - Cisco Nexus 7000 Series Switches, Juniper Networks Inc. JunOS до 21.2R3-S3, Juniper Networks Inc. JunOS до 21.3R3-S1, Juniper Networks Inc. JunOS до 21.4R2-S2, Juniper Networks Inc. JunOS до 21.4R3, Juniper Networks Inc. JunOS до 22.1R1-S2, Juniper Networks Inc. JunOS до 22.1R2, Juniper Networks Inc. JunOS до 22.1R3, Juniper Networks Inc. JunOS до 22.2R2, Juniper Networks Inc. JunOS до 22.3R1, Juniper Networks Inc. JunOS до 22.1R3-EVO, Juniper Networks Inc. JunOS до 22.2R2-EVO, Juniper Networks Inc. JunOS до 22.3R1-EVO, Juniper Networks Inc. JunOS до 22.4R1-EVO

Mitigations

Установка обновлений из доверенных источников. В связи со сложившейся обстановкой и введенными санкциями против Российской Федерации рекомендуется устанавливать обновления программного обеспечения только после оценки всех сопутствующих рисков. Компенсирующие меры: - настройка оборудования на отказ в приеме пакетов, для которых невозможно определить поле «Ethertype» с использованием списка контроля доступа ACL. Использование рекомендаций: https://kb.cert.org/vuls/id/855201 https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-VU855201-J3z8CKTX

JSON

To clipboard

{
  "CVSS 2.0": "AV:A/AC:L/Au:N/C:N/I:P/A:N",
  "CVSS 3.0": "AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
  "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": "Cisco Systems, Inc., Juniper Networks Inc.",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "- (NX-OS), - (Cisco IOS), - (Cisco IOS XE), - (MS390), - (MS210), - (MS225), - (MS250), - (MS350), - (MS355), - (MS410), - (MS420), - (MS425), - (MS450), - (Business 250 Series Smart Switches), - (Business 350 Series Managed Switches), - (Cisco 350X Series Managed Switches), - (Cisco Small Business 550X Series), \u0434\u043e 21.2R3-S3 (JunOS), \u0434\u043e 21.3R3-S1 (JunOS), \u0434\u043e 21.4R2-S2 (JunOS), \u0434\u043e 21.4R3 (JunOS), \u0434\u043e 22.1R1-S2 (JunOS), \u0434\u043e 22.1R2 (JunOS), \u0434\u043e 22.1R3 (JunOS), \u0434\u043e 22.2R2 (JunOS), \u0434\u043e 22.3R1 (JunOS), \u0434\u043e 22.1R3-EVO (JunOS), \u0434\u043e 22.2R2-EVO (JunOS), \u0434\u043e 22.3R1-EVO (JunOS), \u0434\u043e 22.4R1-EVO (JunOS)",
  "\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": "\u0423\u0441\u0442\u0430\u043d\u043e\u0432\u043a\u0430 \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0439 \u0438\u0437 \u0434\u043e\u0432\u0435\u0440\u0435\u043d\u043d\u044b\u0445 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u043e\u0432.\n\u0412 \u0441\u0432\u044f\u0437\u0438 \u0441\u043e \u0441\u043b\u043e\u0436\u0438\u0432\u0448\u0435\u0439\u0441\u044f \u043e\u0431\u0441\u0442\u0430\u043d\u043e\u0432\u043a\u043e\u0439 \u0438 \u0432\u0432\u0435\u0434\u0435\u043d\u043d\u044b\u043c\u0438 \u0441\u0430\u043d\u043a\u0446\u0438\u044f\u043c\u0438 \u043f\u0440\u043e\u0442\u0438\u0432 \u0420\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u043e\u0439 \u0424\u0435\u0434\u0435\u0440\u0430\u0446\u0438\u0438 \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0443\u0435\u0442\u0441\u044f \u0443\u0441\u0442\u0430\u043d\u0430\u0432\u043b\u0438\u0432\u0430\u0442\u044c \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f \u0442\u043e\u043b\u044c\u043a\u043e \u043f\u043e\u0441\u043b\u0435 \u043e\u0446\u0435\u043d\u043a\u0438 \u0432\u0441\u0435\u0445 \u0441\u043e\u043f\u0443\u0442\u0441\u0442\u0432\u0443\u044e\u0449\u0438\u0445 \u0440\u0438\u0441\u043a\u043e\u0432.\n\n\u041a\u043e\u043c\u043f\u0435\u043d\u0441\u0438\u0440\u0443\u044e\u0449\u0438\u0435 \u043c\u0435\u0440\u044b:\n- \u043d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0430 \u043e\u0431\u043e\u0440\u0443\u0434\u043e\u0432\u0430\u043d\u0438\u044f \u043d\u0430 \u043e\u0442\u043a\u0430\u0437 \u0432 \u043f\u0440\u0438\u0435\u043c\u0435 \u043f\u0430\u043a\u0435\u0442\u043e\u0432, \u0434\u043b\u044f \u043a\u043e\u0442\u043e\u0440\u044b\u0445 \u043d\u0435\u0432\u043e\u0437\u043c\u043e\u0436\u043d\u043e \u043e\u043f\u0440\u0435\u0434\u0435\u043b\u0438\u0442\u044c \u043f\u043e\u043b\u0435 \u00abEthertype\u00bb \u0441 \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435\u043c \u0441\u043f\u0438\u0441\u043a\u0430 \u043a\u043e\u043d\u0442\u0440\u043e\u043b\u044f \u0434\u043e\u0441\u0442\u0443\u043f\u0430 ACL.\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:\nhttps://kb.cert.org/vuls/id/855201\nhttps://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-VU855201-J3z8CKTX",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "27.09.2022",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "13.09.2024",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "28.09.2022",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2022-05987",
  "\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-2021-27853",
  "\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": "NX-OS, Cisco IOS, Cisco IOS XE, MS390, MS210, MS225, MS250, MS350, MS355, MS410, MS420, MS425, MS450, Business 250 Series Smart Switches, Business 350 Series Managed Switches, Cisco 350X Series Managed Switches, Cisco Small Business 550X Series, JunOS",
  "\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": "Cisco Systems, Inc. NX-OS - Nexus 9000 Series in Standalone NX-OS Mode, Cisco Systems, Inc. Cisco IOS - Cisco Catalyst 6500, Cisco Systems, Inc. Cisco IOS - Cisco Catalyst 6800 Series, Cisco Systems, Inc. Cisco IOS - Catalyst Digital Building Series Switches, Cisco Systems, Inc. Cisco IOS - Industrial Ethernet Switches, Cisco Systems, Inc. Cisco IOS - Micro Switches, Cisco Systems, Inc. Cisco IOS XE - Cisco Catalyst 4500 Series, Cisco Systems, Inc. Cisco IOS XE - IOS XE Switches, Cisco Systems, Inc. NX-OS - Cisco Nexus 3000 Series, Cisco Systems, Inc. NX-OS - Cisco Nexus 5500 Platform Switches, Cisco Systems, Inc. NX-OS - Cisco Nexus 5600 Platform Switches, Cisco Systems, Inc. NX-OS - Cisco Nexus 6000 Series Switches, Cisco Systems, Inc. NX-OS - Cisco Nexus 7000 Series Switches, Juniper Networks Inc. JunOS \u0434\u043e 21.2R3-S3 , Juniper Networks Inc. JunOS \u0434\u043e 21.3R3-S1 , Juniper Networks Inc. JunOS \u0434\u043e 21.4R2-S2 , Juniper Networks Inc. JunOS \u0434\u043e 21.4R3 , Juniper Networks Inc. JunOS \u0434\u043e 22.1R1-S2 , Juniper Networks Inc. JunOS \u0434\u043e 22.1R2 , Juniper Networks Inc. JunOS \u0434\u043e 22.1R3 , Juniper Networks Inc. JunOS \u0434\u043e 22.2R2 , Juniper Networks Inc. JunOS \u0434\u043e 22.3R1 , Juniper Networks Inc. JunOS \u0434\u043e 22.1R3-EVO , Juniper Networks Inc. JunOS \u0434\u043e 22.2R2-EVO , Juniper Networks Inc. JunOS \u0434\u043e 22.3R1-EVO , Juniper Networks Inc. JunOS \u0434\u043e 22.4R1-EVO ",
  "\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 \u0440\u0435\u0430\u043b\u0438\u0437\u0430\u0446\u0438\u0438 \u043f\u0440\u043e\u0442\u043e\u043a\u043e\u043b\u0430 \u0438\u043d\u043a\u0430\u043f\u0441\u0443\u043b\u044f\u0446\u0438\u0438 Ethernet, \u0441\u0432\u044f\u0437\u0430\u043d\u043d\u0430\u044f \u0441 \u0432\u043e\u0437\u043c\u043e\u0436\u043d\u043e\u0441\u0442\u044c\u044e \u043e\u0431\u044a\u0435\u0434\u0438\u043d\u0435\u043d\u0438\u044f \u0437\u0430\u0433\u043e\u043b\u043e\u0432\u043a\u043e\u0432, \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 \u0438\u043b\u0438 \u0440\u0435\u0430\u043b\u0438\u0437\u043e\u0432\u0430\u0442\u044c \u0430\u0442\u0430\u043a\u0443 \u00ab\u0447\u0435\u043b\u043e\u0432\u0435\u043a \u043f\u043e\u0441\u0435\u0440\u0435\u0434\u0438\u043d\u0435\u00bb (MITM)",
  "\u041d\u0430\u043b\u0438\u0447\u0438\u0435 \u044d\u043a\u0441\u043f\u043b\u043e\u0439\u0442\u0430": "\u0421\u0443\u0449\u0435\u0441\u0442\u0432\u0443\u0435\u0442 \u0432 \u043e\u0442\u043a\u0440\u044b\u0442\u043e\u043c \u0434\u043e\u0441\u0442\u0443\u043f\u0435",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "\u041e\u0431\u0445\u043e\u0434 \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u0438 \u043f\u043e\u0441\u0440\u0435\u0434\u0441\u0442\u0432\u043e\u043c \u0441\u043f\u0443\u0444\u0438\u043d\u0433\u0430 (CWE-290)",
  "\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 \u0440\u0435\u0430\u043b\u0438\u0437\u0430\u0446\u0438\u0438 \u043f\u0440\u043e\u0442\u043e\u043a\u043e\u043b\u0430 \u0438\u043d\u043a\u0430\u043f\u0441\u0443\u043b\u044f\u0446\u0438\u0438 Ethernet \u0441\u0432\u044f\u0437\u0430\u043d\u0430 \u0441 \u0432\u043e\u0437\u043c\u043e\u0436\u043d\u043e\u0441\u0442\u044c\u044e \u043e\u0431\u044a\u0435\u0434\u0438\u043d\u0435\u043d\u0438\u044f \u0437\u0430\u0433\u043e\u043b\u043e\u0432\u043a\u043e\u0432. \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, \u0434\u0435\u0439\u0441\u0442\u0432\u0443\u044e\u0449\u0435\u043c\u0443 \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e, \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 \u0438\u043b\u0438 \u0440\u0435\u0430\u043b\u0438\u0437\u043e\u0432\u0430\u0442\u044c \u0430\u0442\u0430\u043a\u0443 \u00ab\u0447\u0435\u043b\u043e\u0432\u0435\u043a \u043f\u043e\u0441\u0435\u0440\u0435\u0434\u0438\u043d\u0435\u00bb (MITM)",
  "\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": "\u041d\u0430\u0440\u0443\u0448\u0435\u043d\u0438\u0435 \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u0438",
  "\u0421\u0441\u044b\u043b\u043a\u0438 \u043d\u0430 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u0438": "https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/\t\nhttps://standards.ieee.org/ieee/802.1Q/10323/\t\nhttps://standards.ieee.org/ieee/802.2/1048/\t\nhttps://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-VU855201-J3z8CKTX\nhttps://kb.cert.org/vuls/id/855201\nhttps://blog.champtar.fr/VLAN0_LLC_SNAP/",
  "\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, \u041f\u041e \u0441\u0435\u0442\u0435\u0432\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e-\u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u0433\u043e \u0441\u0440\u0435\u0434\u0441\u0442\u0432\u0430, \u0421\u0435\u0442\u0435\u0432\u043e\u0435 \u0441\u0440\u0435\u0434\u0441\u0442\u0432\u043e, \u0421\u0435\u0442\u0435\u0432\u043e\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0435 \u0441\u0440\u0435\u0434\u0441\u0442\u0432\u043e, \u041f\u041e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e-\u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u0433\u043e \u0441\u0440\u0435\u0434\u0441\u0442\u0432\u0430",
  "\u0422\u0438\u043f \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "CWE-290",
  "\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": "\u041d\u0438\u0437\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 2.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 3,3)\n\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 3.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 4,7)"
}

CVE-2021-27853 (GCVE-0-2021-27853)

Vulnerability from cvelistv5 – Published: 2022-09-27 17:55 – Updated: 2025-11-04 19:12

Title

L2 network filtering can be bypassed using stacked VLAN0 and LLC/SNAP headers

Summary

Layer 2 network filtering capabilities such as IPv6 RA guard or ARP inspection can be bypassed using combinations of VLAN 0 headers and LLC/SNAP headers.

Severity

4.7 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2025-05-21 15:26 UTC

CWE

CWE-290 - Authentication Bypass by Spoofing

Assigner

certcc mitre root

References

7 references

URL	Tags
https://datatracker.ietf.org/doc/draft-ietf-v6ops…
https://standards.ieee.org/ieee/802.2/1048/
https://standards.ieee.org/ieee/802.1Q/10323/
https://tools.cisco.com/security/center/content/C…	vendor-advisory
https://kb.cert.org/vuls/id/855201
https://blog.champtar.fr/VLAN0_LLC_SNAP/
https://www.kb.cert.org/vuls/id/855201

Impacted products

3 products

Vendor	Product	Version
IEEE	802.2	Affected: 802.2h-1997 , ≤ 802.2h-1997 (custom)
IETF	draft-ietf-v6ops-ra-guard	Affected: 08 , ≤ 08 (custom)
IETF	P802.1Q	Affected: D1.0 , ≤ D1.0 (custom)

Date Public

2022-09-27 00:00

Credits

Etienne Champetier (@champtar) <champetier.etienne@gmail.com>

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2025-11-04T19:12:25.432Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://standards.ieee.org/ieee/802.2/1048/"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://standards.ieee.org/ieee/802.1Q/10323/"
          },
          {
            "name": "20220927 Vulnerabilities in Layer 2 Network Security Controls Affecting Cisco Products: September 2022",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-VU855201-J3z8CKTX"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://kb.cert.org/vuls/id/855201"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://blog.champtar.fr/VLAN0_LLC_SNAP/"
          },
          {
            "url": "https://www.kb.cert.org/vuls/id/855201"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "ADJACENT_NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 4.7,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "NONE",
              "integrityImpact": "LOW",
              "privilegesRequired": "NONE",
              "scope": "CHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2021-27853",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-05-21T15:26:49.324466Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-05-21T15:27:39.621Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "802.2",
          "vendor": "IEEE",
          "versions": [
            {
              "lessThanOrEqual": "802.2h-1997",
              "status": "affected",
              "version": "802.2h-1997",
              "versionType": "custom"
            }
          ]
        },
        {
          "product": "draft-ietf-v6ops-ra-guard",
          "vendor": "IETF",
          "versions": [
            {
              "lessThanOrEqual": "08",
              "status": "affected",
              "version": "08",
              "versionType": "custom"
            }
          ]
        },
        {
          "product": "P802.1Q",
          "vendor": "IETF",
          "versions": [
            {
              "lessThanOrEqual": "D1.0",
              "status": "affected",
              "version": "D1.0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Etienne Champetier (@champtar) \u003cchampetier.etienne@gmail.com\u003e"
        }
      ],
      "datePublic": "2022-09-27T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Layer 2 network filtering capabilities such as IPv6 RA guard or ARP inspection can be bypassed using combinations of VLAN 0 headers and LLC/SNAP headers."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-290",
              "description": "CWE-290: Authentication Bypass by Spoofing",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2022-10-12T00:00:00.000Z",
        "orgId": "37e5125f-f79b-445b-8fad-9564f167944b",
        "shortName": "certcc"
      },
      "references": [
        {
          "url": "https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/"
        },
        {
          "url": "https://standards.ieee.org/ieee/802.2/1048/"
        },
        {
          "url": "https://standards.ieee.org/ieee/802.1Q/10323/"
        },
        {
          "name": "20220927 Vulnerabilities in Layer 2 Network Security Controls Affecting Cisco Products: September 2022",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-VU855201-J3z8CKTX"
        },
        {
          "url": "https://kb.cert.org/vuls/id/855201"
        },
        {
          "url": "https://blog.champtar.fr/VLAN0_LLC_SNAP/"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "L2 network filtering can be bypassed using stacked VLAN0 and LLC/SNAP headers"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "37e5125f-f79b-445b-8fad-9564f167944b",
    "assignerShortName": "certcc",
    "cveId": "CVE-2021-27853",
    "datePublished": "2022-09-27T17:55:09.203Z",
    "dateReserved": "2021-03-01T00:00:00.000Z",
    "dateUpdated": "2025-11-04T19:12:25.432Z",
    "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.

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.

Action not permitted

BDU:2022-05987 (CVE-2021-27853)

CVE-2021-27853 (GCVE-0-2021-27853)

Tags

Sightings

Nomenclature

Related by attack behaviour