CVE-2021-45488

Name: CVE-2021-45488
Creator: NVD / NIST
Published: 2021-12-25T02:15:06.803+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.96%

Last modified Jun 17, 2026

CVE-2021-45488 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. In NetBSD through 9.2, there is an information leak in the TCP ISN (ISS) generation algorithm.. EPSS estimates a 0.96% chance of exploitation in the next 30 days.

Description

In NetBSD through 9.2, there is an information leak in the TCP ISN (ISS) generation algorithm.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

0.96%

57.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-330

Affected Software

Vendor	Product	Versions
Netbsd	Netbsd	<= 9.2

References

http://ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2021-001.txt.ascPatch, Vendor Advisory
https://arxiv.org/pdf/2112.09604.pdfTechnical Description, Third Party Advisory
http://ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2021-001.txt.ascPatch, Vendor Advisory
https://arxiv.org/pdf/2112.09604.pdfTechnical Description, Third Party Advisory

Timeline

Published: Dec 25, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-45488?

In NetBSD through 9.2, there is an information leak in the TCP ISN (ISS) generation algorithm.

How severe is CVE-2021-45488?

CVE-2021-45488 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.96% probability of exploitation in the next 30 days.

How do I fix CVE-2021-45488?

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-2021-45488?

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

Scan your code now

Source: NVD / NIST