VULNERABILITY INTELLIGENCE
CVE-2005-4440
CVSS score5 MEDIUM
EPSS probability1.61%
CISA KEVNot currently listed
Published2005-12-21
Last modified2026-06-16
CVSS vectorAV:N/AC:L/Au:N/C:N/I:P/A:N
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."