Description
The ntpd client in NTP 4.x before 4.2.8p4 and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service via a number of crafted "KOD" messages.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 11 | ntp | 1:4.2.8p4+dfsg-3 | — |
| Debian 8 | ntp | 1:4.2.6.p5+dfsg-7+deb8u1 | DSA-3388-1 |
| Debian 7 | ntp | 1:4.2.6.p5+dfsg-2+deb7u6 | DSA-3388-1 |
| Debian 6.0 | ntp | 1:4.2.6.p2+dfsg-1+deb6u4 | DLA-335-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | ntp | 1:4.2.6.p5+dfsg-3ubuntu2.14.04.5 | USN-2783-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | ntp +4 | 4.2.6p5-19.ael7b_1.3 | RHSA-2015:1930 |
| RHEL 6 | ntp +3 | 4.2.6p5-5.el6_7.2 | RHSA-2015:1930 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6.6 EUS | ntp +3 | 4.2.6p5-3.el6_6.1 | RHSA-2015:2520 |
| RHEL 6.5 EUS | ntp +3 | 4.2.6p5-2.el6_5.1 | RHSA-2015:2520 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP1 | ntp | 4.2.8p7-11.1 | SUSE-SU-2016:1291-1 |
| SLES 12 | ntp | 4.2.8p6-46.5.2 | SUSE-SU-2016:1568-1, SUSE-SU-2016:1247-1 |
| SLES 12 | yast2-ntp-client | 3.1.12.4-8.2 | SUSE-SU-2016:1247-1 |
| SLES 11 SP4 | ntp | 4.2.8p4-5.1 | SUSE-SU-2016:1278-1, SUSE-SU-2015:2058-1 |
| SLES 11 SP3 | ntp | 4.2.8p6-41.1 | SUSE-SU-2016:1471-1, SUSE-SU-2016:1311-1 |
| SLES 11 SP2 | ntp | 4.2.8p6-41.1 | SUSE-SU-2016:1471-1, SUSE-SU-2016:1311-1 |
| SLES 11 SP2 | yast2-ntp-client | 2.17.14.1-1.12.1 | SUSE-SU-2016:1311-1 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP1 | ntp | 4.2.8p7-11.1 | SUSE-SU-2016:1291-1 |
| SLES for SAP 12 | ntp | 4.2.8p6-46.5.2 | SUSE-SU-2016:1568-1, SUSE-SU-2016:1247-1 |
| SLES for SAP 12 | yast2-ntp-client | 3.1.12.4-8.2 | SUSE-SU-2016:1247-1 |
| SLES for SAP 11 SP4 | ntp | 4.2.8p4-5.1 | SUSE-SU-2016:1278-1, SUSE-SU-2015:2058-1 |
| SUSE OpenStack Cloud 5 | ntp | 4.2.8p6-41.1 | SUSE-SU-2016:1471-1, SUSE-SU-2016:1311-1 |
| SUSE Manager Proxy 2.1 | ntp | 4.2.8p6-41.1 | SUSE-SU-2016:1471-1, SUSE-SU-2016:1311-1 |
| SUSE Manager 2.1 | ntp | 4.2.8p6-41.1 | SUSE-SU-2016:1471-1, SUSE-SU-2016:1311-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | ntp | 4.2.8p9-1.1 | openSUSE-SU-2024:10181-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | ntp +4 | 4.2.6p5-19.el7_1.3 | ELSA-2015-1930 |
Advisories 16
- RHSA-2015:1930 Red Hat Security Advisory: ntp security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2015:2520 Red Hat Security Advisory: ntp security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DLA-335-1 ntp - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3388-1 ntp - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-2783-1 ntp vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2016:1311-1 Security update for ntp SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:2058-1 Security update for ntp SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:1247-1 Security update for ntp SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10181-1 ntp-4.2.8p9-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:1471-1 Security update for ntp SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:1568-1 Security update for ntp SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:1291-1 Security update for ntp SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:1278-1 Security update for ntp SUSE / openSUSE Security Updates · Feb 4, 2026
- ICSA-15-356-01 Siemens RUGGEDCOM ROX-based Devices NTP Vulnerabilities CISA ICS & IT advisories · Jun 9, 2025
- VDE-2022-032 AUMA: Multiple Vulnerabilities in Automation Runtime NTP Service CERT@VDE · Aug 9, 2022
- ELSA-2015-1930 Important: ntp security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Oct 26, 2015
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1271070
- RHSA-2015:1930 vendor-advisory
- 77280 vdb-entry
- VU#718152 third-party-advisory
- http://bugs.ntp.org/show_bug.cgi?id=2901
- https://support.citrix.com/article/CTX220112
- http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
- https://security.netapp.com/advisory/ntap-20171004-0002/
- 1033951 vdb-entry
- http://support.ntp.org/bin/view/Main/SecurityNotice#October_2015_NTP_4_2_8p4_Securit
- DSA-3388 vendor-advisory
- https://www.cs.bu.edu/~goldbe/NTPattack.html
- https://eprint.iacr.org/2015/1020.pdf
- https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05270839
- RHSA-2015:2520 vendor-advisory
- http://support.ntp.org/bin/view/Main/NtpBug2901
- GLSA-201607-15 vendor-advisory
- https://security.netapp.com/advisory/ntap-20171004-0001/
- https://kc.mcafee.com/corporate/index?page=content&id=SB10284
- https://www.arista.com/en/support/advisories-notices/security-advisories/1212-security-advisory-0016