What is CVE-2018-7183?

CVE-2018-7183 is a critical-severity vulnerability in FreeBSD, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2018-03-08.

How severe is CVE-2018-7183?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2018-7183 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in FreeBSD

CVE-2018-7183

Buffer overflow in the decodearr function in ntpq in ntp 4.2.8p6 through 4.2.8p10 allows remote attackers to execute arbitrary code by leveraging an ntpq query and sending a response with a crafted array.

Vulnerability class: Buffer Overflow

Published 2018-03-08 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.102 (95.5th percentile), scored 2026-09-29.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 96th percentile — 95.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.102 · newest: 0.102 · change: 0.000

Affected products

FreeBSD — versions 10.3, 10.4, 11.1
NetApp Element Software
NTP — versions 4.2.8
Canonical Ubuntu Linux — versions 12.04, 14.04, 16.04

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

Public proof-of-concept exploits

ARPSyndicate/cvemon

References

security.gentoo.org/glsa/201805-12 (vendor-advisory, Third Party Advisory)
security.FreeBSD.org/advisories/FreeBSD-SA-18:02.ntp.asc (vendor-advisory, Third Party Advisory)
usn.ubuntu.com/3707-2/ (vendor-advisory, Third Party Advisory)
usn.ubuntu.com/3707-1/ (vendor-advisory, Third Party Advisory)
www.securityfocus.com/bid/103351 (VDB Entry, Third Party Advisory, vdb-entry)
www.oracle.com//security-alerts/cpujul2021.html
security.netapp.com/advisory/ntap-20180626-0001/ (Third Party Advisory)
support.ntp.org/bin/view/Main/SecurityNotice (Vendor Advisory)
www.synology.com/support/security/Synology_SA_18_13 (Third Party Advisory)
support.ntp.org/bin/view/Main/NtpBug3414 (Vendor Advisory)

Frequently asked questions

What is CVE-2018-7183?: CVE-2018-7183 is a critical-severity vulnerability in FreeBSD, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2018-03-08.
How severe is CVE-2018-7183?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2018-7183 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.