CVE-2020-3231Cisco IOS Software for Catalyst 2960-L Series Switches and Catalyst CDB-8P Switches 802.1X Authentication Bypass Vulnerability
- 4.7MediumCVSS base score
- 0.45%Exploitation in 30 daysEPSS · top 60% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A vulnerability in the 802.1X feature of Cisco Catalyst 2960-L Series Switches and Cisco Catalyst CDB-8P Switches could allow an unauthenticated, adjacent attacker to forward broadcast traffic before being authenticated on the port. The vulnerability exists because broadcast traffic that is received on the 802.1X-enabled port is mishandled. An attacker could exploit this vulnerability by sending broadcast traffic on the port before being authenticated. A successful exploit could allow the attacker to send and receive broadcast traffic on the 802.1X-enabled port before authentication.
Timeline
ID reserved
By cisco
- 6 months later
· 6 months later
Published
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ciscoCNA (assigner) | 3.0 | Medium4.7 | CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N |
| NVDNVD · Modified | 3.1 | Medium4.7 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.45% · top 60% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.7.
Affected products
- affected n/a
What to do
Exploitation: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
References
References1
- 20200603 Cisco IOS Software for Catalyst 2960-L Series Switches and Catalyst CDB-8P Switches 802.1X Authentication Bypass Vulnerability (opens in a new tab)vendor-advisoryx_refsource_CISCOx_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)
- EUVD EUVD-2020-24502 (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://cveledger.app/cve/CVE-2020-3231)Record last updated .