Vulnerability in Ieee 802.2
CVE-2021-27861
Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length (and optionally VLAN0 headers)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.007 (49.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.007 · change: +0.001
Affected products
- Ieee 802.2 — versions 802.2h-1997
- Ieee 802.2
- Ietf Draft-Ietf-V6ops-Ra-Guard — versions 08
- Ietf P802.1q — versions D1.0
Weakness classification (CWE)
References
- datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/ (Third Party Advisory)
- standards.ieee.org/ieee/802.2/1048/ (Third Party Advisory)
- standards.ieee.org/ieee/802.1Q/10323/ (Third Party Advisory)
- kb.cert.org/vuls/id/855201
- blog.champtar.fr/VLAN0_LLC_SNAP/
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2021-27861?
- CVE-2021-27861 is a medium-severity vulnerability in Ieee 802.2, classified under Improper Handling of Length Parameter Inconsistency. CVSS score: 4.7/10. Published 2022-09-27.
- How severe is CVE-2021-27861?
- Medium severity. CVSS v3 base score is 4.7 out of 10.