CVE-2025-20253

HIGH
Published Aug 14, 2025 Modified Apr 15, 2026 CWE-835

Description

A vulnerability in the IKEv2 feature of Cisco IOS Software, IOS XE Software, Secure Firewall ASA Software, and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to reload, resulting in a DoS condition. This vulnerability is due to the improper processing of IKEv2 packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device. A successful exploit could allow the attacker to cause an infinite loop that exhausts resources and could cause the device to reload.

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CVSS v3.1 Score

8.6
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Weakness Type (CWE)

CWE-835 CWE-835

References

Frequently Asked Questions

What is CVE-2025-20253? +
A vulnerability in the IKEv2 feature of Cisco IOS Software, IOS XE Software, Secure Firewall ASA Software, and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to reload, resulting in a DoS condition. This vulnerability is due to the improper processing of IKEv2 packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device. A successful exploit could allow the attacker to cause an infinite loop that exhausts resources and could cause the device to reload. It has a CVSS v3.1 base score of 8.6 (HIGH).
How severe is CVE-2025-20253? +
CVE-2025-20253 has a CVSS v3.1 score of 8.6 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
How do I check if I'm vulnerable to CVE-2025-20253? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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