Back
CVE-2005-4440
The 802.1q VLAN protocol allows remote attackers to bypass network segmentation and spoof VLAN traffic via a message with two 802.1q tags,…
Medium5.0EPSS 1.6%
- Published
- Updated
- Reserved
- Assigned by
- mitre
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."
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 2.0 | Medium5.0 | AV:N/AC:L/Au:N/C:N/I:P/A:N |
- EPSS (exploitation in 30 days)
- 1.6% · top 24% of all CVEs (4 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.0.
Weakness
- n/a
Affected products
n/a
- affected n/a
References (3)
- 20051219 Making unidirectional VLAN and PVLAN jumping bidirectional (opens in a new tab)mailing-listx_refsource_BUGTRAQx_transferred
- 20051219 Making unidirectional VLAN and PVLAN jumping bidirectional (opens in a new tab)mailing-listx_refsource_FULLDISCx_transferred
- 20051219 Re: Making unidirectional VLAN and PVLAN jumping bidirectional (opens in a new tab)mailing-listx_refsource_BUGTRAQx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2005-4440)Record last updated .