CVE-2025-20224: A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco Secure Firewall Adaptive Securi

Routine

MEDIUM 5.8REMOTEDOWNGRADEMITIGATE

CVE-2025-20224 is a medium-severity flaw (CVSS 5.8) affecting secure firewall threat defense, adaptive security appliance software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a memory leak, resulting in a denial of service (DoS) condition. This vulnerability is due to improper parsing of IKEv2 packets. An attacker could exploit this vulnerability by sending a continuous st

Why this priority

Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.8 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 46%)
CISA exploited list	No
Weakness	CWE-401
Published	2025-08-14
Last modified	2026-09-18

Publisher (CNA): Cisco Systems, Inc. · Vendor: cisco

Last updated 2026-09-18 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-08-14 17:15 UTCPublished CVE record published
2026-09-18 13:18 UTCUpdated Record last modified

cisco secure firewall threat defense DOWNGRADE

Affected: 6.2.3 · 6.2.3.1 · 6.2.3.2 · 6.2.3.3 · 6.2.3.4 · 6.2.3.5 · 6.2.3.6 · 6.2.3.7

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.2.3

1. Check installed version

apt-cache policy secure-firewall-threat-defense || rpm -q secure-firewall-threat-defense || secure-firewall-threat-defense --version

2. No fixed release: DOWNGRADE to a release before 6.2.3 (Debian / Ubuntu)

apt-cache madison secure-firewall-threat-defense sudo apt install secure-firewall-threat-defense=<VERSION_BEFORE_6.2.3> sudo apt-mark hold secure-firewall-threat-defense

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list secure-firewall-threat-defense sudo dnf downgrade secure-firewall-threat-defense-<VERSION_BEFORE_6.2.3> sudo dnf versionlock add secure-firewall-threat-defense

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

cisco adaptive security appliance software MITIGATE

Affected: 9.8.1 · 9.8.1.5 · 9.8.1.7 · 9.8.2 · 9.8.2.8 · 9.8.2.14 · 9.8.2.15 · 9.8.2.17

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.8.1

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-20224?

secure firewall threat defense: downgrade or apply the listed mitigation; adaptive security appliance software: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-20224 being exploited?

CVE-2025-20224 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-20224 affect?

CVE-2025-20224 affects secure firewall threat defense, adaptive security appliance software. Severity is medium (CVSS 5.8). A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to t

How urgent is CVE-2025-20224?

Priority 39/100. Remotely exploitable, no login, no user action

Software pages

Cisco ASA vulnerabilities · Cisco vulnerabilities

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References

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