How severe is CVE-2021-45488?

CVE-2021-45488 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-45488 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-45488?

CVE-2021-45488 affects Netbsd. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-45488?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-45488 published?

CVE-2021-45488 was published on 2021-12-25 and last updated on 2026-06-17.

CVE-2021-45488

CVE-2021-45488 is a high-severity vulnerability in Netbsd with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-330.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-330
Affected product: Netbsd
Published: 2021-12-25
Last modified: 2026-06-17

Description

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

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 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-45488 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-45488?: CVE-2021-45488 affects Netbsd. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-45488?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-45488 published?: CVE-2021-45488 was published on 2021-12-25 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:netbsd:netbsd:*:*:*:*:*:*:*:*

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