What is CVE-2017-6459?

CVE-2017-6459 is a medium-severity vulnerability in NTP, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 5.5/10. Published 2017-03-27.

How severe is CVE-2017-6459?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Buffer overflow in NTP

CVE-2017-6459

The Windows installer for NTP before 4.2.8p10 and 4.3.x before 4.3.94 allows local users to have unspecified impact via vectors related to an argument with multiple null bytes.

Vulnerability class: Buffer Overflow

Published 2017-03-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (32.5th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 32.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

NTP — versions 4.2.8, 4.3.0, 4.3.1

Weakness classification (CWE)

CWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer

References

www.securitytracker.com/id/1038123 (VDB Entry, Third Party Advisory, vdb-entry)
support.apple.com/HT208144
support.ntp.org/bin/view/Main/NtpBug3382 (Vendor Advisory)
www.securityfocus.com/bid/97076 (VDB Entry, Third Party Advisory, vdb-entry)
support.ntp.org/bin/view/Main/SecurityNotice (Vendor Advisory)

Frequently asked questions

What is CVE-2017-6459?: CVE-2017-6459 is a medium-severity vulnerability in NTP, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 5.5/10. Published 2017-03-27.
How severe is CVE-2017-6459?: Medium severity. CVSS v3 base score is 5.5 out of 10.