Description
NTP before 4.2.8p9 changes the peer structure to the interface it receives the response from a source, which allows remote attackers to cause a denial of service (prevent communication with a source) by sending a response for a source to an interface the source does not use.
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 | 1:4.2.8p9+dfsg-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | ntp | 1:4.2.8p4+dfsg-3ubuntu5.5 | USN-3349-1 |
| Ubuntu 14.04 LTS | ntp | 1:4.2.6.p5+dfsg-3ubuntu2.14.04.11 | USN-3349-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | ntp +4 | 4.2.6p5-25.el7_3.1 | RHSA-2017:0252 |
| RHEL 6 | ntp +3 | 4.2.6p5-10.el6_8.2 | RHSA-2017:0252 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | ntp | 4.2.8p9-55.1 | SUSE-SU-2016:3195-1 |
| SLES 12 SP1 | ntp | 4.2.8p9-55.1 | SUSE-SU-2016:3195-1 |
| SLES 12 | ntp | 4.2.8p9-46.18.1 | SUSE-SU-2016:3196-1 |
| SLES 11 SP4 | ntp | 4.2.8p9-57.2 | SUSE-SU-2016:3193-1 |
| SLES 11 SP3 | ntp | 4.2.8p9-48.9.1 | SUSE-SU-2017:0255-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 SP2 | ntp | 4.2.8p9-48.9.1 | SUSE-SU-2017:0255-1 |
| SLES for SAP 12 SP2 | ntp | 4.2.8p9-55.1 | SUSE-SU-2016:3195-1 |
| SLES for SAP 12 SP1 | ntp | 4.2.8p9-55.1 | SUSE-SU-2016:3195-1 |
| SLES for SAP 12 | ntp | 4.2.8p9-46.18.1 | SUSE-SU-2016:3196-1 |
| SLES for SAP 11 SP4 | ntp | 4.2.8p9-57.2 | SUSE-SU-2016:3193-1 |
| SUSE OpenStack Cloud 5 | ntp | 4.2.8p9-48.9.1 | SUSE-SU-2017:0255-1 |
| SUSE Manager Proxy 2.1 | ntp | 4.2.8p9-48.9.1 | SUSE-SU-2017:0255-1 |
| SUSE Manager 2.1 | ntp | 4.2.8p9-48.9.1 | SUSE-SU-2017:0255-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | ntp | 4.2.8p9-48.9.1 | SUSE-SU-2017:0255-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | ntp | 4.2.8p9-1.1 | openSUSE-SU-2024:10181-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | ntp +4 | 4.2.6p5-28.amzn2.2.1 | ALAS2-2018-1009 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | ntp +4 | 4.2.6p5-25.0.1.el7_3.1 | ELSA-2017-0252 |
Advisories 10
- RHSA-2017:0252 Red Hat Security Advisory: ntp security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-3349-1 ntp vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2016:3193-1 Security update for ntp SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:3195-1 Security update for ntp SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:0255-1 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-2016:3196-1 Security update for ntp SUSE / openSUSE Security Updates · May 2, 2025
- VDE-2022-032 AUMA: Multiple Vulnerabilities in Automation Runtime NTP Service CERT@VDE · Aug 9, 2022
- ALAS2-2018-1009 Moderate: ntp security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · May 10, 2018
- ELSA-2017-0252 Moderate: ntp security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Feb 6, 2017
References
- https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03706en_us
- RHSA-2017:0252 vendor-advisory
- http://support.ntp.org/bin/view/Main/SecurityNotice#Recent_Vulnerabilities
- http://nwtime.org/ntp428p9_release/
- VU#633847 third-party-advisory
- http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
- 1037354 vdb-entry
- https://bto.bluecoat.com/security-advisory/sa139
- 94453 vdb-entry
- http://support.ntp.org/bin/view/Main/NtpBug3072