CVE-2021-27861 (GCVE-0-2021-27861)

Vulnerability from cvelistv5 – Published: 2022-09-27 18:40 – Updated: 2025-11-04 19:12
VLAI?
Summary
Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length (and optionally VLAN0 headers)
Severity ?
4.7 (Medium)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
CWE
  • CWE-130 - Improper Handling of Length Parameter
  • CWE-290 - Authentication Bypass by Spoofing
Assigner
References
Impacted products
Vendor Product Version
IEEE 802.2 Affected: 802.2h-1997 , ≤ 802.2h-1997 (custom)
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    IETF draft-ietf-v6ops-ra-guard Affected: 08 , ≤ 08 (custom)
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    IETF P802.1Q Affected: D1.0 , ≤ D1.0 (custom)
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Credits
Etienne Champetier (@champtar) <champetier.etienne@gmail.com>
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Sightings

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  • 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.