---
id: CVE-2024-20436
title: Cisco IOS and IOS XE Software WebUI Denial of Service Vulnerability
summary: "A vulnerability in the HTTP Server feature of Cisco IOS XE Software when the Telephony Service feature is enabled could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.\r\n\r\nThis v…"
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 3.9.1S
  - ios_xe_software 3.10.0S
  - ios_xe_software 3.10.1S
  - ios_xe_software 3.10.2S
  - ios_xe_software 3.11.1S
  - ios_xe_software 3.12.0S
  - ios_xe_software 3.11.2S
  - ios_xe_software 3.13.0S
  - ios_xe_software 3.10.3S
  - ios_xe_software 3.10.4S
  - ios_xe_software 3.9.2S
  - ios_xe_software 3.11.0S
  - ios_xe_software 3.10.5S
  - ios_xe_software 3.11.3S
  - ios_xe_software 3.12.1S
  - ios_xe_software 3.12.2S
  - ios_xe_software 3.13.1S
  - ios_xe_software 3.13.2S
  - ios_xe_software 3.12.3S
  - ios_xe_software 3.14.0S
  - ios_xe_software 3.15.0S
  - ios_xe_software 3.14.1S
  - ios_xe_software 3.10.6S
  - ios_xe_software 3.11.4S
  - ios_xe_software 3.14.2S
  - ios_xe_software 3.14.3S
  - ios_xe_software 3.14.4S
  - ios_xe_software 3.13.3S
  - ios_xe_software 3.15.1S
  - ios_xe_software 3.16.0S
  - ios_xe_software 3.15.2S
  - ios_xe_software 3.17.0S
  - ios_xe_software 3.17.1S
  - ios_xe_software 3.10.2aS
  - ios_xe_software 3.10.2tS
  - ios_xe_software 3.10.7S
  - ios_xe_software 3.12.4S
  - ios_xe_software 3.13.4S
  - ios_xe_software 3.16.1aS
  - ios_xe_software 3.16.2S
published: '2024-09-25'
updated: '2024-09-25'
sourceUpdated: '2024-09-25T16:00:00+00:00'
source: CSAF
sourceUrl: >-
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-httpsrvr-dos-yOZThut
references:
  - url: >-
      https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-httpsrvr-dos-yOZThut
  - url: 'https://software.cisco.com'
tags:
  - csaf
  - vendor-advisory
  - cisco
epss: 0.0086
epssPercentile: 0.57617
ingestedAt: '2026-10-15T11:50:11.865Z'
---

## Overview

A vulnerability in the HTTP Server feature of Cisco IOS XE Software when the Telephony Service feature is enabled could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.

This vulnerability is due to a null pointer dereference when accessing specific URLs. An attacker could exploit this vulnerability by sending crafted HTTP traffic to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, causing a DoS condition on the affected device.

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



This advisory is part of the September 2024 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 2024 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75169"].

## Vendor advisories

- **cisco-sa-httpsrvr-dos-yOZThut** · Cisco · affected: Cisco IOS XE Software (215 versions) · updated 2024-09-25 · [advisory](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-httpsrvr-dos-yOZThut)

**Cisco IOS XE Software HTTP Server Telephony Services Denial of Service Vulnerability**. Released 2024-09-25.

Affected:

- Cisco IOS XE Software 3.9.1S
- Cisco IOS XE Software 3.10.0S
- Cisco IOS XE Software 3.10.1S
- Cisco IOS XE Software 3.10.2S
- Cisco IOS XE Software 3.11.1S
- Cisco IOS XE Software 3.12.0S
- Cisco IOS XE Software 3.11.2S
- Cisco IOS XE Software 3.13.0S
- Cisco IOS XE Software 3.10.3S
- Cisco IOS XE Software 3.10.4S
- Cisco IOS XE Software 3.9.2S
- Cisco IOS XE Software 3.11.0S
- Cisco IOS XE Software 3.10.5S
- Cisco IOS XE Software 3.11.3S
- Cisco IOS XE Software 3.12.1S
- Cisco IOS XE Software 3.12.2S
- Cisco IOS XE Software 3.13.1S
- Cisco IOS XE Software 3.13.2S
- Cisco IOS XE Software 3.12.3S
- Cisco IOS XE Software 3.14.0S
- Cisco IOS XE Software 3.15.0S
- Cisco IOS XE Software 3.14.1S
- Cisco IOS XE Software 3.10.6S
- Cisco IOS XE Software 3.11.4S
- Cisco IOS XE Software 3.14.2S
- Cisco IOS XE Software 3.14.3S
- Cisco IOS XE Software 3.14.4S
- Cisco IOS XE Software 3.13.3S
- Cisco IOS XE Software 3.15.1S
- Cisco IOS XE Software 3.16.0S
- Cisco IOS XE Software 3.15.2S
- Cisco IOS XE Software 3.17.0S
- Cisco IOS XE Software 3.17.1S
- Cisco IOS XE Software 3.10.2aS
- Cisco IOS XE Software 3.10.2tS
- Cisco IOS XE Software 3.10.7S
- Cisco IOS XE Software 3.12.4S
- Cisco IOS XE Software 3.13.4S
- Cisco IOS XE Software 3.16.1aS
- Cisco IOS XE Software 3.16.2S

## Remediation

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