HOME VULNERABILITIESCVE-2016-4954

HIGH

CVE-2016-4954

CWE-362Published: July 5, 2016· Updated: Jun 17, 2026

7.5

CVSS v3.1

Official Description

The process_packet function in ntp_proto.c in ntpd in NTP 4.x before 4.2.8p8 allows remote attackers to cause a denial of service (peer-variable modification) by sending spoofed packets from many source IP addresses in a certain scenario, as demonstrated by triggering an incorrect leap indication.

Technical Analysis

CVE-2016-4954 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Affected Vendors & Products

ntp1 product(s)

ntp

openSUSE2 product(s)

leapopensuse

Oracle1 product(s)

solaris

siemens6 product(s)

simatic net cp 443-1 opc ua firmwaresimatic net cp 443-1 opc uatim 4r-ie firmwaretim 4r-ietim 4r-ie dnp3 firmwaretim 4r-ie dnp3

SUSE5 product(s)

managermanager proxyopenstack cloudlinux enterprise desktoplinux enterprise server

Source: NVD CPE · 18 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

Security advisories & exploits

Official NIST entry

CVE Program entry

External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttp://support.ntp.org/bin/view/Main/NtpBug3044

PATCHhttp://support.ntp.org/bin/view/Main/NtpBug3044

ADVISORYhttp://bugs.ntp.org/3044

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00018.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00023.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00024.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00028.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00040.html

ADVISORYhttp://support.ntp.org/bin/view/Main/SecurityNotice

ADVISORYhttp://www.kb.cert.org/vuls/id/321640

ADVISORYhttp://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html

ADVISORYhttp://www.securitytracker.com/id/1036037

ADVISORYhttps://cert-portal.siemens.com/productcert/pdf/ssa-211752.pdf

ADVISORYhttps://cert-portal.siemens.com/productcert/pdf/ssa-497656.pdf

ADVISORYhttps://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03757en_us

ADVISORYhttps://security.FreeBSD.org/advisories/FreeBSD-SA-16:24.ntp.asc

ADVISORYhttps://security.gentoo.org/glsa/201607-15

ADVISORYhttps://us-cert.cisa.gov/ics/advisories/icsa-21-103-11

ADVISORYhttp://bugs.ntp.org/3044

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00018.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00023.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00024.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00028.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00040.html

ADVISORYhttp://support.ntp.org/bin/view/Main/SecurityNotice

ADVISORYhttp://www.kb.cert.org/vuls/id/321640

ADVISORYhttp://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html

ADVISORYhttp://www.securitytracker.com/id/1036037

ADVISORYhttps://cert-portal.siemens.com/productcert/pdf/ssa-211752.pdf

ADVISORYhttps://cert-portal.siemens.com/productcert/pdf/ssa-497656.pdf

ADVISORYhttps://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03757en_us

ADVISORYhttps://security.FreeBSD.org/advisories/FreeBSD-SA-16:24.ntp.asc

ADVISORYhttps://security.gentoo.org/glsa/201607-15

ADVISORYhttps://us-cert.cisa.gov/ics/advisories/icsa-21-103-11

All References (70)

→

http://bugs.ntp.org/3044Issue Tracking · Vendor Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00018.htmlMailing List · Third Party Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00020.html

→

http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00023.htmlMailing List · Third Party Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00024.htmlMailing List · Third Party Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00028.htmlMailing List · Third Party Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00040.htmlMailing List · Third Party Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00026.html

→

http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00042.html

→

http://packetstormsecurity.com/files/137321/Slackware-Security-Advisory-ntp-Updates.html

→

http://packetstormsecurity.com/files/137322/FreeBSD-Security-Advisory-FreeBSD-SA-16-24.ntp.html

→

http://support.ntp.org/bin/view/Main/NtpBug3044Patch · Vendor Advisory

→

http://support.ntp.org/bin/view/Main/SecurityNoticeVendor Advisory

→

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160603-ntpd

→

http://www.kb.cert.org/vuls/id/321640Third Party Advisory · US Government Resource

Quick Facts

CVE IDCVE-2016-4954

CVSS Score7.5 / 10

SeverityHIGH

WeaknessCWE-362

CISA KEVNo

Affected5 vendor(s)

PublishedJul 5, 2016

Related CVEs (CWE-362)

Recommended Actions

→Apply vendor patches immediately
→Monitor CVE-2016-4954 in threat intel feeds
→Review IDS/IPS signatures for exploitation attempts

Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.

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