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CVE-2025-20209

HIGHCVSS 7.5/10EPSS 0.51%

Last modified

CVE-2025-20209 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. A vulnerability in the Internet Key Exchange version 2 (IKEv2) function of Cisco IOS XR Software could allow an unauthenticated, remote attacker to prevent an affected device from processing any control plane UDP packets.  This vulnerability is due to improper handling of malformed IKEv2 packets. An attacker could exploit this vulnerability by sending malformed IKEv2 packets to an affected device. EPSS estimates a 0.51% chance of exploitation in the next 30 days.

Description

A vulnerability in the Internet Key Exchange version 2 (IKEv2) function of Cisco IOS XR Software could allow an unauthenticated, remote attacker to prevent an affected device from processing any control plane UDP packets.  This vulnerability is due to improper handling of malformed IKEv2 packets. An attacker could exploit this vulnerability by sending malformed IKEv2 packets to an affected device. A successful exploit could allow the attacker to prevent the affected device from processing any control plane UDP packets, resulting in a denial of service (DoS) condition. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

Metrics

CVSS 3.1
7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.51%

39.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
CiscoIos Xr6.5.1
CiscoIos Xr6.5.2
CiscoIos Xr6.5.3
CiscoIos Xr6.6.1
CiscoIos Xr6.6.2
CiscoIos Xr6.6.3
CiscoIos Xr6.6.25
CiscoIos Xr7.0.0
CiscoIos Xr7.0.1
CiscoIos Xr7.0.2
CiscoIos Xr7.1.1
CiscoIos Xr7.1.2
CiscoIos Xr7.2.0
CiscoIos Xr7.2.1
CiscoIos Xr7.2.2
CiscoIos Xr7.3.1
CiscoIos Xr7.3.2
CiscoIos Xr7.3.27
CiscoIos Xr7.4.1
CiscoIos Xr7.4.2
CiscoIos Xr7.5.1
CiscoIos Xr7.5.2
CiscoIos Xr7.6.1
CiscoIos Xr7.6.2
CiscoIos Xr7.7.1
CiscoIos Xr7.7.2
CiscoIos Xr7.7.21
CiscoIos Xr7.8.1
CiscoIos Xr7.8.2
CiscoIos Xr7.8.22
CiscoIos Xr7.9.1
CiscoIos Xr7.9.2
CiscoIos Xr7.10.1
CiscoIos Xr7.10.2
CiscoIos Xr7.11.1
CiscoIos Xr7.11.2
CiscoIos Xr24.1.1
CiscoIos Xr24.1.2
CiscoIos Xr24.2.1
CiscoIos Xr24.2.11

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2025-20209?
A vulnerability in the Internet Key Exchange version 2 (IKEv2) function of Cisco IOS XR Software could allow an unauthenticated, remote attacker to prevent an affected device from processing any control plane UDP packets.  This vulnerability is due to improper handling of malformed IKEv2 packets. An attacker could exploit this vulnerability by sending malformed IKEv2 packets to an affected device. A successful exploit could allow the attacker to prevent the affected device from processing any control plane UDP packets, resulting in a denial of service (DoS) condition. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.
How severe is CVE-2025-20209?
CVE-2025-20209 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.51% probability of exploitation in the next 30 days.
How do I fix CVE-2025-20209?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-20209?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST