---
id: CVE-2023-20033
title: >-
  Cisco IOS XE Software for Catalyst 3650 and Catalyst 3850 Switches Denial of
  Service  Vulnerability
summary: >-
  A vulnerability in Cisco IOS XE Software for Cisco Catalyst 3650 and Catalyst
  3850 Series Switches could allow an unauthenticated, remote attacker to cause
  an affected device to reload unexpectedly, resulting in a denial of service
  (DoS) c…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'
cvssSource: vendor
vendor: Cisco
product: Cisco IOS XE Software
affected:
  - ios_xe_software 16.3.1
  - ios_xe_software 16.4.1
  - ios_xe_software 16.3.2
  - ios_xe_software 16.3.3
  - ios_xe_software 16.5.1
  - ios_xe_software 16.6.1
  - ios_xe_software 16.7.1
  - ios_xe_software 16.8.1
  - ios_xe_software 16.3.1a
  - ios_xe_software 16.3.4
  - ios_xe_software 16.5.1a
  - ios_xe_software 16.9.1
  - ios_xe_software 16.11.1
  - ios_xe_software 16.12.1
  - ios_xe_software 16.6.2
  - ios_xe_software 16.3.5
  - ios_xe_software 16.3.5b
  - ios_xe_software 16.3.6
  - ios_xe_software 16.6.3
  - ios_xe_software 16.9.2
  - ios_xe_software 16.6.4
  - ios_xe_software 16.8.1a
  - ios_xe_software 16.8.1s
  - ios_xe_software 16.3.7
  - ios_xe_software 16.6.5
  - ios_xe_software 16.9.1s
  - ios_xe_software 16.6.4s
  - ios_xe_software 16.6.4a
  - ios_xe_software 16.9.3
  - ios_xe_software 16.3.8
  - ios_xe_software 16.9.2s
  - ios_xe_software 16.6.6
  - ios_xe_software 16.6.7
  - ios_xe_software 16.11.1s
  - ios_xe_software 16.3.9
  - ios_xe_software 16.9.4
  - ios_xe_software 16.9.3s
  - ios_xe_software 16.9.3a
  - ios_xe_software 16.11.1c
  - ios_xe_software 16.12.1s
published: '2023-09-27'
updated: '2023-09-27'
sourceUpdated: '2023-09-27T16:00:00+00:00'
source: CSAF
sourceUrl: >-
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cat3k-dos-ZZA4Gb3r
references:
  - url: >-
      https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cat3k-dos-ZZA4Gb3r
  - url: 'https://software.cisco.com'
tags:
  - csaf
  - vendor-advisory
  - cisco
epss: 0.00653
epssPercentile: 0.49895
ingestedAt: '2026-09-08T15:58:18.536Z'
---

## Overview

A vulnerability in Cisco IOS XE Software for Cisco Catalyst 3650 and Catalyst 3850 Series Switches could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition.

This vulnerability is due to improper resource management when processing traffic that is received on the management interface. An attacker could exploit this vulnerability by sending a high rate of traffic to the management interface. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.



This advisory is part of the September 2023 release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: September 2023 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-74916"].

## Vendor advisories

- **cisco-sa-cat3k-dos-ZZA4Gb3r** · Cisco · affected: Cisco IOS XE Software (63 versions) · updated 2023-09-27 · [advisory](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cat3k-dos-ZZA4Gb3r)

**Cisco IOS XE Software for Catalyst 3650 and Catalyst 3850 Series Switches Denial of Service Vulnerability**. Released 2023-09-27.

Affected:

- Cisco IOS XE Software 16.3.1
- Cisco IOS XE Software 16.4.1
- Cisco IOS XE Software 16.3.2
- Cisco IOS XE Software 16.3.3
- Cisco IOS XE Software 16.5.1
- Cisco IOS XE Software 16.6.1
- Cisco IOS XE Software 16.7.1
- Cisco IOS XE Software 16.8.1
- Cisco IOS XE Software 16.3.1a
- Cisco IOS XE Software 16.3.4
- Cisco IOS XE Software 16.5.1a
- Cisco IOS XE Software 16.9.1
- Cisco IOS XE Software 16.11.1
- Cisco IOS XE Software 16.12.1
- Cisco IOS XE Software 16.6.2
- Cisco IOS XE Software 16.3.5
- Cisco IOS XE Software 16.3.5b
- Cisco IOS XE Software 16.3.6
- Cisco IOS XE Software 16.6.3
- Cisco IOS XE Software 16.9.2
- Cisco IOS XE Software 16.6.4
- Cisco IOS XE Software 16.8.1a
- Cisco IOS XE Software 16.8.1s
- Cisco IOS XE Software 16.3.7
- Cisco IOS XE Software 16.6.5
- Cisco IOS XE Software 16.9.1s
- Cisco IOS XE Software 16.6.4s
- Cisco IOS XE Software 16.6.4a
- Cisco IOS XE Software 16.9.3
- Cisco IOS XE Software 16.3.8
- Cisco IOS XE Software 16.9.2s
- Cisco IOS XE Software 16.6.6
- Cisco IOS XE Software 16.6.7
- Cisco IOS XE Software 16.11.1s
- Cisco IOS XE Software 16.3.9
- Cisco IOS XE Software 16.9.4
- Cisco IOS XE Software 16.9.3s
- Cisco IOS XE Software 16.9.3a
- Cisco IOS XE Software 16.11.1c
- Cisco IOS XE Software 16.12.1s

## Remediation

Cisco has released software updates that address this vulnerability. https://software.cisco.com