How severe is CVE-2019-11331?

CVE-2019-11331 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2019-11331 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-11331?

CVE-2019-11331 affects Ntp. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-11331?

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-2019-11331 published?

CVE-2019-11331 was published on 2019-04-18 and last updated on 2026-06-17.

CVE-2019-11331

CVE-2019-11331 is a high-severity vulnerability in Ntp with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 6.8
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Ntp
Published: 2019-04-18
Last modified: 2026-06-17

Description

Network Time Protocol (NTP), as specified in RFC 5905, uses port 123 even for modes where a fixed port number is not required, which makes it easier for remote attackers to conduct off-path attacks.

Frequently asked questions

What is CVE-2019-11331?: Network Time Protocol (NTP), as specified in RFC 5905, uses port 123 even for modes where a fixed port number is not required, which makes it easier for remote attackers to conduct off-path attacks.
How severe is CVE-2019-11331?: CVE-2019-11331 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2019-11331 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-11331?: CVE-2019-11331 affects Ntp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-11331?: 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-2019-11331 published?: CVE-2019-11331 was published on 2019-04-18 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:ntp:ntp:-:*:*:*:*:*:*:*

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