Medium severity5.9NVD Advisory· Published Jul 5, 2016· Updated Jun 17, 2026

CVE-2016-4955

Description

ntpd in NTP 4.x before 4.2.8p8, when autokey is enabled, allows remote attackers to cause a denial of service (peer-variable clearing and association outage) by sending (1) a spoofed crypto-NAK packet or (2) a packet with an incorrect MAC value at a certain time.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected products

NTP/NTP22 versions
cpe:2.3:a:ntp:ntp:*:*:*:*:*:*:*:*+ 21 more
- cpe:2.3:a:ntp:ntp:*:*:*:*:*:*:*:*range: >=4.2.0,<4.2.8
- cpe:2.3:a:ntp:ntp:4.2.8:-:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p1-beta1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p1-beta2:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p1-beta3:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p1-beta4:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p1-beta5:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p1-rc1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p1-rc2:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p2:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p2-rc1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p2-rc2:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p2-rc3:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p3:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p3-rc1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p3-rc2:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p3-rc3:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p4:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p5:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p6:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.8:p7:*:*:*:*:*:*
SUSE S.A./Manager Proxy
cpe:2.3:a:suse:manager_proxy:2.1:*:*:*:*:*:*:*
SUSE S.A./Openstack Cloud
cpe:2.3:a:suse:openstack_cloud:5:*:*:*:*:*:*:*
Novell/Suse Manager
cpe:2.3:o:novell:suse_manager:2.1:*:*:*:*:*:*:*
OpenSUSE/Leap
cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:*
OpenSUSE/openSUSE
cpe:2.3:o:opensuse:opensuse:13.2:*:*:*:*:*:*:*
Oracle Corporation/Solaris2 versions
cpe:2.3:o:oracle:solaris:10:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:o:oracle:solaris:10:*:*:*:*:*:*:*
- cpe:2.3:o:oracle:solaris:11.3:*:*:*:*:*:*:*
Siemens Foundation/Simatic Net Cp 443 1 Opc Ua Firmware
cpe:2.3:o:siemens:simatic_net_cp_443-1_opc_ua_firmware:*:*:*:*:*:*:*:*
SUSE S.A./Linux Enterprise Desktop
cpe:2.3:o:suse:linux_enterprise_desktop:12:sp1:*:*:*:*:*:*
SUSE S.A./Linux Enterprise Server4 versions
cpe:2.3:o:suse:linux_enterprise_server:11:sp2:*:*:ltss:*:*:*+ 3 more
- cpe:2.3:o:suse:linux_enterprise_server:11:sp2:*:*:ltss:*:*:*
- cpe:2.3:o:suse:linux_enterprise_server:11:sp3:*:*:ltss:*:*:*
- cpe:2.3:o:suse:linux_enterprise_server:11:sp4:*:*:*:*:*:*
- cpe:2.3:o:suse:linux_enterprise_server:12:sp1:*:*:*:*:*:*
NTP/ntpdllm-fuzzy
Range: < 4.2.8p8
osv-coords15 versions
pkg:rpm/opensuse/ntp&distro=openSUSE%20Tumbleweed pkg:rpm/suse/ntp&distro=SUSE%20Linux%20Enterprise%20Desktop%2012 pkg:rpm/suse/ntp&distro=SUSE%20Linux%20Enterprise%20Desktop%2012%20SP1 pkg:rpm/suse/ntp&distro=SUSE%20Linux%20Enterprise%20Server%2011%20SP2-LTSS pkg:rpm/suse/ntp&distro=SUSE%20Linux%20Enterprise%20Server%2011%20SP3-LTSS pkg:rpm/suse/ntp&distro=SUSE%20Linux%20Enterprise%20Server%2011%20SP3-TERADATA pkg:rpm/suse/ntp&distro=SUSE%20Linux%20Enterprise%20Server%2011%20SP4 pkg:rpm/suse/ntp&distro=SUSE%20Linux%20Enterprise%20Server%2012 pkg:rpm/suse/ntp&distro=SUSE%20Linux%20Enterprise%20Server%2012%20SP1 pkg:rpm/suse/ntp&distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2011%20SP4 pkg:rpm/suse/ntp&distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2012 pkg:rpm/suse/ntp&distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2012%20SP1 pkg:rpm/suse/ntp&distro=SUSE%20Manager%202.1 pkg:rpm/suse/ntp&distro=SUSE%20Manager%20Proxy%202.1 pkg:rpm/suse/ntp&distro=SUSE%20OpenStack%20Cloud%205
< 4.2.8p9-1.1+ 14 more
- (no CPE)range: < 4.2.8p9-1.1
- (no CPE)range: < 4.2.8p8-46.8.1
- (no CPE)range: < 4.2.8p8-14.1
- (no CPE)range: < 4.2.8p8-47.3
- (no CPE)range: < 4.2.8p8-47.3
- (no CPE)range: < 4.2.8p8-47.3
- (no CPE)range: < 4.2.8p8-14.1
- (no CPE)range: < 4.2.8p8-46.8.1
- (no CPE)range: < 4.2.8p8-14.1
- (no CPE)range: < 4.2.8p8-14.1
- (no CPE)range: < 4.2.8p8-46.8.1
- (no CPE)range: < 4.2.8p8-14.1
- (no CPE)range: < 4.2.8p8-47.3
- (no CPE)range: < 4.2.8p8-47.3
- (no CPE)range: < 4.2.8p8-47.3

Patches

Vulnerability mechanics

References

support.ntp.org/bin/view/Main/NtpBug3043nvdPatchVendor Advisory
bugs.ntp.org/3043nvdIssue TrackingVendor Advisory
lists.opensuse.org/opensuse-security-announce/2016-06/msg00018.htmlnvdMailing ListThird Party Advisory
lists.opensuse.org/opensuse-security-announce/2016-06/msg00023.htmlnvdMailing ListThird Party Advisory
lists.opensuse.org/opensuse-security-announce/2016-06/msg00024.htmlnvdMailing ListThird Party Advisory
lists.opensuse.org/opensuse-security-announce/2016-06/msg00028.htmlnvdMailing ListThird Party Advisory
lists.opensuse.org/opensuse-security-announce/2016-06/msg00040.htmlnvdMailing ListThird Party Advisory
support.ntp.org/bin/view/Main/SecurityNoticenvdRelease NotesVendor Advisory
www.kb.cert.org/vuls/id/321640nvdThird Party AdvisoryUS Government Resource
www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.htmlnvdThird Party Advisory
www.securityfocus.com/bid/91007nvdThird Party AdvisoryVDB Entry
www.securitytracker.com/id/1036037nvdThird Party AdvisoryVDB Entry
cert-portal.siemens.com/productcert/pdf/ssa-211752.pdfnvdThird Party Advisory
security.freebsd.org/advisories/FreeBSD-SA-16:24.ntp.ascnvdThird Party Advisory
security.gentoo.org/glsa/201607-15nvdThird Party Advisory
lists.opensuse.org/opensuse-security-announce/2016-06/msg00020.htmlnvd
lists.opensuse.org/opensuse-security-announce/2016-07/msg00026.htmlnvd
lists.opensuse.org/opensuse-security-announce/2016-08/msg00042.htmlnvd
packetstormsecurity.com/files/137321/Slackware-Security-Advisory-ntp-Updates.htmlnvd
packetstormsecurity.com/files/137322/FreeBSD-Security-Advisory-FreeBSD-SA-16-24.ntp.htmlnvd
tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160603-ntpdnvd
www.securityfocus.com/archive/1/538599/100/0/threadednvd
www.securityfocus.com/archive/1/538600/100/0/threadednvd
www.securityfocus.com/archive/1/archive/1/538599/100/0/threadednvd
www.securityfocus.com/archive/1/archive/1/538600/100/0/threadednvd
www.ubuntu.com/usn/USN-3096-1nvd
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/K3EYJQHJZ2KTVQ7ICEFHXTLZ36MRASWX/nvd
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ORAMN3Q7TVJ54MBYF75XCJOE3DP7LYHT/nvd
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WNWGCQLW2VY72NIUYMJOCAKJKTXHDUK2/nvd
us-cert.cisa.gov/ics/advisories/icsa-21-159-11nvd
www.kb.cert.org/vuls/id/321640nvd

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cvss	0.384
epss	0.007
exploit	0.000
kev	0.000
patch	0.000
ransomware	0.000