{"id":"CVE-2020-3510","aliases":["EUVD-2020-24781","GHSA-9f77-7fxg-mppm"],"status":"published","title":"Cisco IOS XE Software for Catalyst 9200 Series Switches Umbrella Connector Denial of Service Vulnerability","description":"A vulnerability in the Umbrella Connector component of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches could allow an unauthenticated, remote attacker to trigger a reload, resulting in a denial of service condition on an affected device. The vulnerability is due to insufficient error handling when parsing DNS requests. An attacker could exploit this vulnerability by sending a series of malicious DNS requests to an Umbrella Connector client interface of an affected device. A successful exploit could allow the attacker to cause a crash of the iosd process, which triggers a reload of the affected device.","severity":{"version":"3.0","score":8.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.01375,"percentile":0.72215,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-388","CWE-400"],"published":"2020-09-24T17:51:44Z","modified":"2026-06-17T03:18:28Z","products":[{"vendor":"cisco","product":"cisco ios xe software"},{"vendor":"cisco","product":"ios_xe"}],"references":[{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-umbrella-dos-t2QMUX37","tags":["vendor-advisory","x_refsource_CISCO","x_transferred","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-3510"},{"url":"https://github.com/advisories/GHSA-9f77-7fxg-mppm"}],"sources":{"cve":[{"id":"CVE-2020-3510","title":"Cisco IOS XE Software for Catalyst 9200 Series Switches Umbrella Connector Denial of Service Vulnerability","description":"A vulnerability in the Umbrella Connector component of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches could allow an unauthenticated, remote attacker to trigger a reload, resulting in a denial of service condition on an affected device. The vulnerability is due to insufficient error handling when parsing DNS requests. An attacker could exploit this vulnerability by sending a series of malicious DNS requests to an Umbrella Connector client interface of an affected device. A successful exploit could allow the attacker to cause a crash of the iosd process, which triggers a reload of the affected device.","status":"published","published":"2020-09-24T17:51:44.121Z","modified":"2024-11-13T18:00:31.25Z","cvss":[{"version":"3.0","score":8.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-388"],"updated_at":"2026-11-02T14:35:51.563355Z"}],"euvd":[{"id":"EUVD-2020-24781","description":"A vulnerability in the Umbrella Connector component of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches could allow an unauthenticated, remote attacker to trigger a reload, resulting in a denial of service condition on an affected device. The vulnerability is due to insufficient error handling when parsing DNS requests. An attacker could exploit this vulnerability by sending a series of malicious DNS requests to an Umbrella Connector client interface of an affected device. A successful exploit could allow the attacker to cause a crash of the iosd process, which triggers a reload of the affected device.","status":"published","published":"2020-09-24T17:51:44Z","modified":"2024-11-13T18:00:31Z","cvss":[{"version":"3.0","score":8.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-03T00:05:01.673157Z"}],"ghsa":[{"id":"GHSA-9f77-7fxg-mppm","title":"A vulnerability in the Umbrella Connector component of Cisco IOS XE Software for Cisco Catalyst...","description":"A vulnerability in the Umbrella Connector component of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches could allow an unauthenticated, remote attacker to trigger a reload, resulting in a denial of service condition on an affected device. The vulnerability is due to insufficient error handling when parsing DNS requests. An attacker could exploit this vulnerability by sending a series of malicious DNS requests to an Umbrella Connector client interface of an affected device. A successful exploit could allow the attacker to cause a crash of the iosd process, which triggers a reload of the affected device.","status":"published","published":"2022-05-24T17:29:29Z","modified":"2023-01-29T05:03:59Z","updated_at":"2026-11-02T14:45:27.054092Z"}],"nvd":[{"id":"CVE-2020-3510","description":"A vulnerability in the Umbrella Connector component of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches could allow an unauthenticated, remote attacker to trigger a reload, resulting in a denial of service condition on an affected device. The vulnerability is due to insufficient error handling when parsing DNS requests. An attacker could exploit this vulnerability by sending a series of malicious DNS requests to an Umbrella Connector client interface of an affected device. A successful exploit could allow the attacker to cause a crash of the iosd process, which triggers a reload of the affected device.","status":"published","published":"2020-09-24T18:15:21.15Z","modified":"2026-06-17T03:18:28.253Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"3.0","score":8.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"2.0","score":7.1,"vector":"AV:N/AC:M/Au:N/C:N/I:N/A:C","level":"high","assessor":"primary"}],"cwes":["CWE-388","CWE-400"],"updated_at":"2026-11-02T14:06:17.70091Z"}]}}