{"id":"CVE-2005-4440","aliases":["EUVD-2005-4435","GHSA-9rvj-pj6p-4pj6"],"status":"published","title":"The 802.1q VLAN protocol allows remote attackers to bypass network segmentation and spoof VLAN...","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.\"","severity":{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-07","score":0.01611,"percentile":0.76093,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"published":"2005-12-21T02:00:00Z","modified":"2026-06-16T22:18:48Z","products":[{"vendor":"vlan_protocol","product":"vlan_protocol"}],"references":[{"url":"http://www.securityfocus.com/archive/1/419831/100/0/threaded","tags":["mailing-list","x_refsource_BUGTRAQ","x_transferred"]},{"url":"http://lists.grok.org.uk/pipermail/full-disclosure/2005-December/040333.html","tags":["mailing-list","x_refsource_FULLDISC","x_transferred"]},{"url":"http://www.securityfocus.com/archive/1/419834/100/0/threaded","tags":["mailing-list","x_refsource_BUGTRAQ","x_transferred"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2005-4440"},{"url":"https://github.com/advisories/GHSA-9rvj-pj6p-4pj6"}],"sources":{"cve":[{"id":"CVE-2005-4440","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.\"","status":"published","published":"2005-12-21T02:00:00Z","modified":"2024-08-07T23:46:04.843Z","updated_at":"2026-11-02T14:33:39.259087Z"}],"euvd":[{"id":"EUVD-2005-4435","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.\"","status":"published","published":"2005-12-21T02:00:00Z","modified":"2024-08-07T23:46:04Z","updated_at":"2026-11-03T01:15:22.811795Z"}],"ghsa":[{"id":"GHSA-9rvj-pj6p-4pj6","title":"The 802.1q VLAN protocol allows remote attackers to bypass network segmentation and spoof VLAN...","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.\"","status":"published","published":"2022-05-01T02:27:15Z","modified":"2023-01-30T05:08:28Z","updated_at":"2026-11-02T14:47:50.107277Z"}],"nvd":[{"id":"CVE-2005-4440","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.\"","status":"published","published":"2005-12-21T02:03:00Z","modified":"2026-06-16T22:18:48.103Z","cvss":[{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"updated_at":"2026-11-02T14:00:58.826417Z"}]}}