---
id: CVE-2025-20253
title: >-
  Cisco IOS, IOS XE, Secure Firewall Adaptive Security Appliance, and Secure
  Firewall Threat Defense Software IKEv2 Denial of Service Vulnera…
summary: >-
  Multiple vulnerabilities in the Internet Key Exchange Version 2 (IKEv2)
  feature of Cisco IOS Software, Cisco IOS XE Software, Cisco Secure Firewall
  Adaptive Security Appliance (ASA) Software, and Cisco Secure Firewall Threat
  Defense (FTD) …
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:
  - firepower_2100_series
  - firepower_1000_series
  - asa_5500_x_series_firewalls
  - 3000_series_industrial_security_appliances_isa
  - firepower_9000_series
  - firepower_4100_series
  - secure_firewall_threat_defense_virtual
  - secure_firewall_3100_series
  - secure_firewall_4200_series
  - secure_firewall_1200_series
  - adaptive_security_virtual_appliance_asav
  - ios 15.1(2)T
  - ios 15.1(1)T4
  - ios 15.3(1)T
  - ios 15.1(3)T2
  - ios 15.1(1)T1
  - ios 15.1(1)XB3
  - ios 15.1(4)M3
  - ios 15.1(2)GC
  - ios 15.1(1)XB1
  - ios 15.1(1)XB2
  - ios 15.1(2)T0a
  - ios 15.1(1)SG
  - ios 15.1(3)T3
  - ios 15.1(1)T3
  - ios 15.1(2)T3
  - ios 15.1(2)T4
  - ios 15.2(4)M
  - ios 15.1(1)T2
  - ios 15.1(3)T
  - ios 15.1(2)T2a
  - ios 15.1(3)T1
  - ios 15.1(1)T
  - ios 15.1(2)T2
  - ios 15.1(2)T1
  - ios 15.0(2)SE
  - ios 15.1(4)M
  - ios 15.1(4)M1
  - ios 15.1(4)M2
  - ios 15.1(4)M6
published: '2025-08-14'
updated: '2025-08-14'
sourceUpdated: '2025-08-14T16:00:00+00:00'
source: CSAF
sourceUrl: >-
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-ios-dos-DOESHWHy
references:
  - url: >-
      https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-ios-dos-DOESHWHy
  - url: 'https://software.cisco.com'
tags:
  - csaf
  - vendor-advisory
  - cisco
epss: 0.00469
epssPercentile: 0.39044
ingestedAt: '2026-10-15T11:50:11.864Z'
---

## Overview

Multiple vulnerabilities in the Internet Key Exchange Version 2 (IKEv2) feature of Cisco IOS Software, Cisco IOS XE Software, Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition.

Cisco has released software updates that address these vulnerabilities. There are workarounds that address these vulnerabilities.

For more information about these vulnerabilities, see the Details ["#details"] section of this advisory.



This advisory is part of the August 2025 release of the Cisco Secure Firewall ASA, Secure FMC, and Secure FTD Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: August 2025 Semiannual Cisco Secure Firewall ASA, Secure FMC, and Secure FTD Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75415"].

## Vendor advisories

- **cisco-sa-asa-ftd-ios-dos-DOESHWHy** · Cisco · affected: Cisco Firepower 2100 Series, Cisco Firepower 1000 Series, Cisco ASA 5500-X Series Firewalls, Cisco 3000 Series Industrial Security Appliances (ISA), Cisco Firepower 9000 Series, Cisco Firepower 4100 Series, … · updated 2025-08-14 · [advisory](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-ios-dos-DOESHWHy)

**Cisco IOS, IOS XE, Secure Firewall Adaptive Security Appliance, and Secure Firewall Threat Defense Software IKEv2 Denial of Service Vulnerabilities**. Released 2025-08-14.

Affected:

- Cisco Firepower 2100 Series
- Cisco Firepower 1000 Series
- Cisco ASA 5500-X Series Firewalls
- Cisco 3000 Series Industrial Security Appliances (ISA)
- Cisco Firepower 9000 Series
- Cisco Firepower 4100 Series
- Cisco Secure Firewall Threat Defense Virtual
- Cisco Secure Firewall 3100 Series
- Cisco Secure Firewall 4200 Series
- Cisco Secure Firewall 1200 Series
- Cisco Adaptive Security Virtual Appliance (ASAv)
- IOS 15.1(2)T
- IOS 15.1(1)T4
- IOS 15.3(1)T
- IOS 15.1(3)T2
- IOS 15.1(1)T1
- IOS 15.1(1)XB3
- IOS 15.1(4)M3
- IOS 15.1(2)GC
- IOS 15.1(1)XB1
- IOS 15.1(1)XB2
- IOS 15.1(2)T0a
- IOS 15.1(1)SG
- IOS 15.1(3)T3
- IOS 15.1(1)T3
- IOS 15.1(2)T3
- IOS 15.1(2)T4
- IOS 15.2(4)M
- IOS 15.1(1)T2
- IOS 15.1(3)T
- IOS 15.1(2)T2a
- IOS 15.1(3)T1
- IOS 15.1(1)T
- IOS 15.1(2)T2
- IOS 15.1(2)T1
- IOS 15.0(2)SE
- IOS 15.1(4)M
- IOS 15.1(4)M1
- IOS 15.1(4)M2
- IOS 15.1(4)M6

## Remediation

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