Cisco IOS XR IKEv2 DoS via Malformed UDP Packets
CVE-2025-20209 Published on March 12, 2025
Cisco IOS XR Software Internet Key Exchange Version 2 Denial of Service Vulnerability
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.
Vulnerability Analysis
CVE-2025-20209 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
Allocation of Resources Without Limits or Throttling
The software allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.
Products Associated with CVE-2025-20209
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Affected Versions
Cisco IOS XR Software:- Version 6.5.3 is affected.
- Version 6.6.1 is affected.
- Version 6.5.2 is affected.
- Version 6.6.2 is affected.
- Version 6.5.1 is affected.
- Version 7.0.1 is affected.
- Version 6.6.25 is affected.
- Version 7.0.0 is affected.
- Version 7.1.1 is affected.
- Version 6.6.3 is affected.
- Version 7.0.2 is affected.
- Version 7.2.0 is affected.
- Version 7.1.2 is affected.
- Version 7.2.1 is affected.
- Version 7.3.1 is affected.
- Version 7.4.1 is affected.
- Version 7.2.2 is affected.
- Version 7.3.2 is affected.
- Version 7.5.1 is affected.
- Version 7.3.27 is affected.
- Version 7.6.1 is affected.
- Version 7.5.2 is affected.
- Version 7.7.1 is affected.
- Version 7.4.2 is affected.
- Version 7.6.2 is affected.
- Version 7.8.1 is affected.
- Version 7.7.2 is affected.
- Version 7.9.1 is affected.
- Version 7.8.2 is affected.
- Version 7.8.22 is affected.
- Version 7.10.1 is affected.
- Version 7.7.21 is affected.
- Version 7.9.2 is affected.
- Version 7.11.1 is affected.
- Version 7.10.2 is affected.
- Version 24.1.1 is affected.
- Version 7.11.2 is affected.
- Version 24.2.1 is affected.
- Version 24.1.2 is affected.
- Version 24.2.11 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.