{"id":"CVE-2025-20311","state":"PUBLISHED","title":"A vulnerability in the handling of certain Ethernet frames in Cisco IOS XE Software for Catalyst 9000 Series Switches could allow an unauthenticated, adjacent attacker to cause an ","description":"A vulnerability in the handling of certain Ethernet frames in Cisco IOS XE Software for Catalyst 9000 Series Switches could allow an unauthenticated, adjacent attacker to cause an egress port to become blocked and drop all outbound traffic.\r\n\r This vulnerability is due to improper handling of crafted Ethernet frames. An attacker could exploit this vulnerability by sending crafted Ethernet frames through an affected switch. A successful exploit could allow the attacker to cause the egress port to which the crafted frame is forwarded to start dropping all frames, resulting in a denial of service (DoS) condition.","publishedAt":"2025-09-24T17:12:06.928Z","updatedAt":"2025-09-30T14:28:26.310Z","severity":{"score":7.4,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","source":"cisco"},"assigner":"cisco","products":["Cisco Cisco IOS XE Software"],"affected":[{"vendor":"Cisco","product":"Cisco IOS XE Software","versions":[{"version":"16.6.1","status":"affected"},{"version":"16.6.2","status":"affected"},{"version":"16.6.3","status":"affected"},{"version":"16.6.4","status":"affected"},{"version":"16.6.5","status":"affected"},{"version":"16.6.4a","status":"affected"},{"version":"16.6.6","status":"affected"},{"version":"16.6.7","status":"affected"},{"version":"16.6.8","status":"affected"},{"version":"16.6.9","status":"affected"},{"version":"16.6.10","status":"affected"},{"version":"16.7.1","status":"affected"},{"version":"16.8.1","status":"affected"},{"version":"16.8.1a","status":"affected"},{"version":"16.8.1s","status":"affected"},{"version":"16.9.1","status":"affected"},{"version":"16.9.2","status":"affected"},{"version":"16.9.1s","status":"affected"},{"version":"16.9.3","status":"affected"},{"version":"16.9.4","status":"affected"},{"version":"16.9.5","status":"affected"},{"version":"16.9.6","status":"affected"},{"version":"16.9.7","status":"affected"},{"version":"16.9.8","status":"affected"},{"version":"16.10.1","status":"affected"},{"version":"16.10.1s","status":"affected"},{"version":"16.10.1e","status":"affected"},{"version":"16.11.1","status":"affected"},{"version":"16.11.1b","status":"affected"},{"version":"16.11.1s","status":"affected"},{"version":"16.12.1","status":"affected"},{"version":"16.12.1s","status":"affected"},{"version":"16.12.1c","status":"affected"},{"version":"16.12.2","status":"affected"},{"version":"16.12.3","status":"affected"},{"version":"16.12.8","status":"affected"},{"version":"16.12.2s","status":"affected"},{"version":"16.12.4","status":"affected"},{"version":"16.12.3s","status":"affected"},{"version":"16.12.3a","status":"affected"},{"version":"16.12.4a","status":"affected"},{"version":"16.12.5","status":"affected"},{"version":"16.12.6","status":"affected"},{"version":"16.12.5b","status":"affected"},{"version":"16.12.6a","status":"affected"},{"version":"16.12.7","status":"affected"},{"version":"16.12.14","status":"affected"},{"version":"17.1.1","status":"affected"},{"version":"17.1.1s","status":"affected"},{"version":"17.1.1t","status":"affected"},{"version":"17.1.3","status":"affected"},{"version":"17.2.1","status":"affected"},{"version":"17.2.1a","status":"affected"},{"version":"17.3.1","status":"affected"},{"version":"17.3.2","status":"affected"},{"version":"17.3.3","status":"affected"},{"version":"17.3.2a","status":"affected"},{"version":"17.3.4","status":"affected"},{"version":"17.3.5","status":"affected"},{"version":"17.3.6","status":"affected"},{"version":"17.3.4b","status":"affected"},{"version":"17.3.7","status":"affected"},{"version":"17.3.8","status":"affected"},{"version":"17.3.8a","status":"affected"},{"version":"17.4.1","status":"affected"},{"version":"17.5.1","status":"affected"},{"version":"17.6.1","status":"affected"},{"version":"17.6.2","status":"affected"},{"version":"17.6.3","status":"affected"},{"version":"17.6.1y","status":"affected"},{"version":"17.6.4","status":"affected"},{"version":"17.6.5","status":"affected"},{"version":"17.6.6","status":"affected"},{"version":"17.6.6a","status":"affected"},{"version":"17.6.5a","status":"affected"},{"version":"17.6.7","status":"affected"},{"version":"17.6.8","status":"affected"},{"version":"17.7.1","status":"affected"},{"version":"17.10.1","status":"affected"},{"version":"17.10.1b","status":"affected"},{"version":"17.8.1","status":"affected"},{"version":"17.9.1","status":"affected"},{"version":"17.9.2","status":"affected"},{"version":"17.9.3","status":"affected"},{"version":"17.9.4","status":"affected"},{"version":"17.9.5","status":"affected"},{"version":"17.9.4a","status":"affected"},{"version":"17.9.6","status":"affected"},{"version":"17.9.6a","status":"affected"},{"version":"17.11.1","status":"affected"},{"version":"17.12.1","status":"affected"},{"version":"17.12.2","status":"affected"},{"version":"17.12.3","status":"affected"},{"version":"17.12.4","status":"affected"},{"version":"17.12.1z3","status":"affected"},{"version":"17.13.1","status":"affected"},{"version":"17.14.1","status":"affected"},{"version":"17.11.99SW","status":"affected"},{"version":"17.15.1","status":"affected"},{"version":"17.15.2","status":"affected"},{"version":"17.15.2a","status":"affected"},{"version":"17.15.2b","status":"affected"},{"version":"17.16.1","status":"affected"}]}],"references":["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cat9k-PtmD7bgy"],"weaknesses":["CWE-19"],"ingestedAt":"2026-10-29T20:08:39.238Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/20xxx/CVE-2025-20311.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2025-20311","state":"PUBLISHED","datePublished":"2025-09-24T17:12:06.928Z","dateUpdated":"2025-09-30T14:28:26.310Z","assignerShortName":"cisco","assignerOrgId":"d1c1063e-7a18-46af-9102-31f8928bc633","dateReserved":"2024-10-10T19:15:13.253Z"},"containers":{"cna":{"descri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vulnerability in the handling of certain Ethernet frames in Cisco IOS XE Software for Catalyst 9000 Series Switches could allow an unauthenticated, adjacent attacker to cause an egress port to become blocked and drop all outbound traffic.\r\n\r This vulnerability is due to improper handling of crafted Ethernet frames. An attacker could exploit this vulnerability by sending crafted Ethernet frames through an affected switch. A successful exploit could allow the attacker to cause the egress port to which the crafted frame is forwarded to start dropping all frames, resulting in a denial of service (DoS) condition."}],"affected":[{"vendor":"Cisco","product":"Cisco IOS XE Software","versions":[{"version":"16.6.1","status":"affected"},{"version":"16.6.2","status":"affected"},{"version":"16.6.3","status":"affected"},{"version":"16.6.4","status":"affected"},{"version":"16.6.5","status":"affected"},{"version":"16.6.4a","status":"affected"},{"version":"16.6.6","status":"affected"},{"version":"16.6.7","status":"affected"},{"version":"16.6.8","status":"affected"},{"version":"16.6.9","status":"affected"},{"version":"16.6.10","status":"affected"},{"version":"16.7.1","status":"affected"},{"version":"16.8.1","status":"affected"},{"version":"16.8.1a","status":"affected"},{"version":"16.8.1s","status":"affected"},{"version":"16.9.1","status":"affected"},{"version":"16.9.2","status":"affected"},{"version":"16.9.1s","status":"affected"},{"version":"16.9.3","status":"affected"},{"version":"16.9.4","status":"affected"},{"version":"16.9.5","status":"affected"},{"version":"16.9.6","status":"affected"},{"version":"16.9.7","status":"affected"},{"version":"16.9.8","status":"affected"},{"version":"16.10.1","status":"affected"},{"version":"16.10.1s","status":"affected"},{"version":"16.10.1e","status":"affected"},{"version":"16.11.1","status":"affected"},{"version":"16.11.1b","status":"affected"},{"version":"16.11.1s","status":"affected"},{"version":"16.12.1","status":"affected"},{"version":"16.12.1s","status":"affected"},{"version":"16.12.1c","status":"affected"},{"version":"16.12.2","status":"affected"},{"version":"16.12.3","status":"affected"},{"version":"16.12.8","status":"affected"},{"version":"16.12.2s","status":"affected"},{"version":"16.12.4","status":"affected"},{"version":"16.12.3s","status":"affected"},{"version":"16.12.3a","status":"affected"},{"version":"16.12.4a","status":"affected"},{"version":"16.12.5","status":"affected"},{"version":"16.12.6","status":"affected"},{"version":"16.12.5b","status":"affected"},{"version":"16.12.6a","status":"affected"},{"version":"16.12.7","status":"affected"},{"version":"16.12.14","status":"affected"},{"version":"17.1.1","status":"affected"},{"version":"17.1.1s","status":"affected"},{"version":"17.1.1t","status":"affected"},{"version":"17.1.3","status":"affected"},{"version":"17.2.1","status":"affected"},{"version":"17.2.1a","status":"affected"},{"version":"17.3.1","status":"affected"},{"version":"17.3.2","status":"affected"},{"version":"17.3.3","status":"affected"},{"version":"17.3.2a","status":"affected"},{"version":"17.3.4","status":"affected"},{"version":"17.3.5","status":"affected"},{"version":"17.3.6","status":"affected"},{"version":"17.3.4b","status":"affected"},{"version":"17.3.7","status":"affected"},{"version":"17.3.8","status":"affected"},{"version":"17.3.8a","status":"affected"},{"version":"17.4.1","status":"affected"},{"version":"17.5.1","status":"affected"},{"version":"17.6.1","status":"affected"},{"version":"17.6.2","status":"affected"},{"version":"17.6.3","status":"affected"},{"version":"17.6.1y","status":"affected"},{"version":"17.6.4","status":"affected"},{"version":"17.6.5","status":"affected"},{"version":"17.6.6","status":"affected"},{"version":"17.6.6a","status":"affected"},{"version":"17.6.5a","status":"affected"},{"version":"17.6.7","status":"affected"},{"version":"17.6.8","status":"affected"},{"version":"17.7.1","status":"affected"},{"version":"17.10.1","status":"affected"},{"version":"17.10.1b","status":"affected"},{"version":"17.8.1","status":"affected"},{"version":"17.9.1","status":"affected"},{"version":"17.9.2","status":"affected"},{"version":"17.9.3","status":"affected"},{"version":"17.9.4","status":"affected"},{"version":"17.9.5","status":"affected"},{"version":"17.9.4a","status":"affected"},{"version":"17.9.6","status":"affected"},{"version":"17.9.6a","status":"affected"},{"version":"17.11.1","status":"affected"},{"version":"17.12.1","status":"affected"},{"version":"17.12.2","status":"affected"},{"version":"17.12.3","status":"affected"},{"version":"17.12.4","status":"affected"},{"version":"17.12.1z3","status":"affected"},{"version":"17.13.1","status":"affected"},{"version":"17.14.1","status":"affected"},{"version":"17.11.99SW","status":"affected"},{"version":"17.15.1","status":"affected"},{"version":"17.15.2","status":"affected"},{"version":"17.15.2a","status":"affected"},{"version":"17.15.2b","status":"affected"},{"version":"17.16.1","status":"affected"}]}],"references":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cat9k-PtmD7bgy","name":"cisco-sa-cat9k-PtmD7bgy"}],"metrics":[{"format":"cvssV3_1","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","baseScore":7.4,"baseSeverity":"HIGH","attackVector":"ADJACENT_NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-19","lang":"en","description":"Data Handling","type":"cwe"}]}],"providerMetadata":{"shortName":"cisco","orgId":"d1c1063e-7a18-46af-9102-31f8928bc633","dateUpdated":"2025-09-30T14:28:26.310Z"},"exploits":[{"lang":"en","value":"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."}],"source":{"advisory":"cisco-sa-cat9k-PtmD7bgy","discovery":"INTERNAL","defects":["CSCwn45401"]}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2025-09-24T18:07:27.423618Z","id":"CVE-2025-20311","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2025-09-24T18:07:39.867Z"}}]}}}