{"id":"CVE-2020-3231","aliases":["EUVD-2020-24502","GHSA-q4w2-p3xv-w8vf"],"status":"published","title":"Cisco IOS Software for Catalyst 2960-L Series Switches and Catalyst CDB-8P Switches 802.1X Authentication Bypass Vulnerability","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.","severity":{"version":"3.0","score":4.7,"vector":"CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00451,"percentile":0.39447,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-284","CWE-863"],"published":"2020-06-03T17:42:27Z","modified":"2026-06-17T03:17:43Z","products":[{"vendor":"cisco","product":"cisco ios 15.2(5a)e"},{"vendor":"cisco","product":"ios"}],"references":[{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-c2960L-DpWA9Re4","tags":["vendor-advisory","x_refsource_CISCO","x_transferred","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-3231"},{"url":"https://github.com/advisories/GHSA-q4w2-p3xv-w8vf"}],"sources":{"cve":[{"id":"CVE-2020-3231","title":"Cisco IOS Software for Catalyst 2960-L Series Switches and Catalyst CDB-8P Switches 802.1X Authentication Bypass Vulnerability","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.","status":"published","published":"2020-06-03T17:42:27.355Z","modified":"2024-11-15T17:13:50.965Z","cvss":[{"version":"3.0","score":4.7,"vector":"CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-284"],"updated_at":"2026-11-02T14:35:51.563355Z"}],"euvd":[{"id":"EUVD-2020-24502","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.","status":"published","published":"2020-06-03T17:42:27Z","modified":"2024-11-15T17:13:50Z","cvss":[{"version":"3.0","score":4.7,"vector":"CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N","level":"medium"}],"updated_at":"2026-11-03T00:04:59.043854Z"}],"ghsa":[{"id":"GHSA-q4w2-p3xv-w8vf","title":"A vulnerability in the 802.1X feature of Cisco Catalyst 2960-L Series Switches and Cisco Catalyst...","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.","status":"published","published":"2022-05-24T17:19:09Z","modified":"2024-04-04T02:52:53Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N","level":"medium"}],"cwes":["CWE-284","CWE-863"],"updated_at":"2026-11-02T14:56:12.690799Z"}],"nvd":[{"id":"CVE-2020-3231","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.","status":"published","published":"2020-06-03T18:15:21.09Z","modified":"2026-06-17T03:17:43.173Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N","level":"medium","assessor":"primary"},{"version":"3.0","score":4.7,"vector":"CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N","level":"medium","assessor":"secondary"},{"version":"2.0","score":2.9,"vector":"AV:A/AC:M/Au:N/C:P/I:N/A:N","level":"low","assessor":"primary"}],"cwes":["CWE-284","CWE-863"],"updated_at":"2026-11-02T14:06:04.922138Z"}]}}