CVE-2005-4440

high

Description

The 802.1q VLAN protocol allows remote attackers to bypass network segmentation and spoof VLAN traffic via a message with two 802.1q tags, which causes the second tag to be redirected from a downstream switch after the first tag has been stripped, as demonstrated by Yersinia, aka "double-tagging VLAN jumping attack."

References

http://www.securityfocus.com/archive/1/419834/100/0/threaded

http://www.securityfocus.com/archive/1/419831/100/0/threaded

http://lists.grok.org.uk/pipermail/full-disclosure/2005-December/040333.html

Details

Source: Mitre, NVD

Published: 2005-12-21

Updated: 2026-06-16

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 7.5

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

Severity: High

EPSS

EPSS: 0.00247