CVE-2020-3510

Cisco IOS XE Software for Catalyst 9200 Series Switches Umbrella Connector Denial of Service Vulnerability

HIGH

8.6

CVSS Score

Published: September 24, 2020 at 05:51 PM UTC

Updated: June 17, 2026 at 03:18 AM UTC

51 products affected across 1 vendorIOS XeCatalyst C9500-48Y4CCatalyst C9200L-24Pxg-4X

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Severity

HIGH8.6

Exploit prediction

EPSS 1%

SSVC

No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

IOS Xe · Cisco

95%

16.12.1 16.12.2 17.1.1

cisco-catalyst-c9200-24p (environment) · cisco-catalyst-c9200-24t (environment) · cisco-catalyst-c9200-48p (environment) · cisco-catalyst-c9200-48t (environment) · cisco-catalyst-c9200l-24p-4g (environment) · cisco-catalyst-c9200l-24p-4x (environment) · cisco-catalyst-c9200l-24pxg-2y (environment) · cisco-catalyst-c9200l-24pxg-4x (environment) · cisco-catalyst-c9200l-24t-4g (environment) · cisco-catalyst-c9200l-24t-4x (environment) · cisco-catalyst-c9200l-48p-4g (environment) · cisco-catalyst-c9200l-48p-4x (environment) · cisco-catalyst-c9200l-48pxg-2y (environment) · cisco-catalyst-c9200l-48pxg-4x (environment) · cisco-catalyst-c9200l-48t-4g (environment) · cisco-catalyst-c9200l-48t-4x (environment) · cisco-catalyst-c9300-24p (environment) · cisco-catalyst-c9300-24s (environment) · cisco-catalyst-c9300-24t (environment) · cisco-catalyst-c9300-24u (environment) · cisco-catalyst-c9300-24ux (environment) · cisco-catalyst-c9300-48p (environment) · cisco-catalyst-c9300-48s (environment) · cisco-catalyst-c9300-48t (environment) · cisco-catalyst-c9300-48u (environment) · cisco-catalyst-c9300-48un (environment) · cisco-catalyst-c9300-48uxm (environment) · cisco-catalyst-c9300l-24p-4g (environment) · cisco-catalyst-c9300l-24p-4x (environment) · cisco-catalyst-c9300l-24t-4g (environment) · cisco-catalyst-c9300l-24t-4x (environment) · cisco-catalyst-c9300l-48p-4g (environment) · cisco-catalyst-c9300l-48p-4x (environment) · cisco-catalyst-c9300l-48t-4g (environment) · cisco-catalyst-c9300l-48t-4x (environment) · cisco-catalyst-c9404r (environment) · cisco-catalyst-c9407r (environment) · cisco-catalyst-c9410r (environment) · cisco-catalyst-c9500-12q (environment) · cisco-catalyst-c9500-16x (environment) · cisco-catalyst-c9500-24q (environment) · cisco-catalyst-c9500-24y4c (environment) · cisco-catalyst-c9500-32c (environment) · cisco-catalyst-c9500-32qc (environment) · cisco-catalyst-c9500-40x (environment) · cisco-catalyst-c9500-48y4c (environment) · cisco-catalyst-c9600-lc-24c (environment) · cisco-catalyst-c9600-lc-48s (environment) · cisco-catalyst-c9600-lc-48tx (environment) · cisco-catalyst-c9600-lc-48yl (environment)

Catalyst C9200-24P · Ciscodevice

80%

All versions

Catalyst C9200-24T · Ciscodevice

80%

All versions

Catalyst C9200-48P · Ciscodevice

80%

All versions

Catalyst C9200-48T · Ciscodevice

80%

All versions