---
id: CVE-2025-20154
title: 'Cisco IOS, IOS XE and IOS XR Software TWAMP Denial of Service Vulnerability'
summary: >-
  A vulnerability in the Two-Way Active Measurement Protocol (TWAMP) server
  feature of Cisco IOS Software and Cisco IOS XE Software could allow an
  unauthenticated, remote attacker to cause the affected device to reload,
  resulting in a denial…
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: IOS
affected:
  - ios_xe_software 3.7.0S
  - ios_xe_software 3.7.1S
  - ios_xe_software 3.7.2S
  - ios_xe_software 3.7.3S
  - ios_xe_software 3.7.4S
  - ios_xe_software 3.8.0S
  - ios_xe_software 3.8.1S
  - ios_xe_software 3.8.2S
  - ios_xe_software 3.9.1S
  - ios_xe_software 3.9.0S
  - ios_xe_software 3.2.0SE
  - ios_xe_software 3.3.0SE
  - ios_xe_software 3.2.1SE
  - ios_xe_software 3.2.2SE
  - ios_xe_software 3.2.3SE
  - ios_xe_software 3.4.0SG
  - ios_xe_software 3.4.2SG
  - ios_xe_software 3.4.1SG
  - ios_xe_software 3.3.1SE
  - ios_xe_software 3.5.0E
  - 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 3.7.5S
  - ios_xe_software 3.7.6S
  - 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 3.4.3SG
  - ios_xe_software 3.4.4SG
  - ios_xe_software 3.4.5SG
published: '2025-05-07'
updated: '2025-05-07'
sourceUpdated: '2025-05-07T16:00:00+00:00'
source: CSAF
sourceUrl: >-
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-twamp-kV4FHugn
references:
  - url: >-
      https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-twamp-kV4FHugn
  - url: 'https://software.cisco.com'
tags:
  - csaf
  - vendor-advisory
  - cisco
epss: 0.00536
epssPercentile: 0.43823
ingestedAt: '2026-10-15T11:50:11.855Z'
---

## Overview

A vulnerability in the Two-Way Active Measurement Protocol (TWAMP) server feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. For Cisco IOS XR Software, this vulnerability could cause the ipsla_ippm_server process to reload unexpectedly if debugs are enabled.

This vulnerability is due to out-of-bounds array access when processing specially crafted TWAMP control packets. An attacker could exploit this vulnerability by sending crafted TWAMP control packets to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

Note: For Cisco IOS XR Software, only the ipsla_ippm_server process reloads unexpectedly and only when debugs are enabled. The vulnerability details for Cisco IOS XR Software are as follows:

    Security Impact Rating (SIR): Low
    CVSS Base Score: 3.7
    CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

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



This advisory is part of the May 2025 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: May 2025 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75279"].

## Vendor advisories

- **cisco-sa-twamp-kV4FHugn** · Cisco · affected: Cisco IOS XE Software (467 versions), IOS (615 versions), Cisco IOS XR Software · updated 2025-05-07 · [advisory](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-twamp-kV4FHugn)

**Cisco IOS, IOS XE, and IOS XR Software TWAMP Denial of Service Vulnerability**. Released 2025-05-07.

Affected:

- Cisco IOS XE Software 3.7.0S
- Cisco IOS XE Software 3.7.1S
- Cisco IOS XE Software 3.7.2S
- Cisco IOS XE Software 3.7.3S
- Cisco IOS XE Software 3.7.4S
- Cisco IOS XE Software 3.8.0S
- Cisco IOS XE Software 3.8.1S
- Cisco IOS XE Software 3.8.2S
- Cisco IOS XE Software 3.9.1S
- Cisco IOS XE Software 3.9.0S
- Cisco IOS XE Software 3.2.0SE
- Cisco IOS XE Software 3.3.0SE
- Cisco IOS XE Software 3.2.1SE
- Cisco IOS XE Software 3.2.2SE
- Cisco IOS XE Software 3.2.3SE
- Cisco IOS XE Software 3.4.0SG
- Cisco IOS XE Software 3.4.2SG
- Cisco IOS XE Software 3.4.1SG
- Cisco IOS XE Software 3.3.1SE
- Cisco IOS XE Software 3.5.0E
- 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 3.7.5S
- Cisco IOS XE Software 3.7.6S
- 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 3.4.3SG
- Cisco IOS XE Software 3.4.4SG
- Cisco IOS XE Software 3.4.5SG

## Remediation

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