CVE-2021-27862

4.7 MEDIUM 0.7% exploit odds Fix listed

What it is

Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length and Ethernet to Wifi frame conversion (and optionally VLAN0 headers).

At a glance

Exploitability: Can be exploited from the same network segment without logging in. Limited direct impact.
Exploit odds: 0.7% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2022-09-27 19:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 03:45 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.7% in the next 30 days (EPSS).
Severity: 4.7 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2022-09-27 19:15 UTC
Last modified: 2026-06-17 03:45 UTC
Exploit probability: 0.7% · EPSS, next 30 days
Weakness: CWE-130
Record status: Modified

Affected

Ieee 802.2 ≤ 802.2h-1997
Ietf p802.1q ≤ d1.0

Attack profile CVSS 3.1 · 4.7

Attack vector: Adjacent network
Complexity: Low
Privileges needed: None
User interaction: None
Scope: Changed
Confidentiality: None
Integrity: Low
Availability: None

Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-27862.md and follow it. Check whether this project is affected by CVE-2021-27862. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record