Description
NTP 4.x before 4.2.8p6 and 4.3.x before 4.3.90 do not verify peer associations of symmetric keys when authenticating packets, which might allow remote attackers to conduct impersonation attacks via an arbitrary trusted key, aka a "skeleton key."
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 | 1:4.2.8p7+dfsg-1 | — |
| Debian 8 | ntp | 1:4.2.6.p5+dfsg-7+deb8u2 | DSA-3629-1 |
| Debian 7 | ntp | 1:4.2.6.p5+dfsg-2+deb7u7 | DLA-559-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | ntp | 1:4.2.8p4+dfsg-3ubuntu5.3 | USN-3096-1 |
| Ubuntu 14.04 LTS | ntp | 1:4.2.6.p5+dfsg-3ubuntu2.14.04.10 | USN-3096-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | ntp +4 | 4.2.6p5-25.el7 | RHSA-2016:2583 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP1 | ntp | 4.2.8p6-8.2 | SUSE-SU-2016:1291-1, SUSE-SU-2016:1177-1 |
| SLES 12 SP1 | yast2-ntp-client | 3.1.22-6.2 | SUSE-SU-2016:1177-1 |
| 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 | 4.2.8p6-8.2 | SUSE-SU-2016:1278-1, SUSE-SU-2016:1175-1 |
| 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 | 4.2.8p6-8.2 | SUSE-SU-2016:1291-1, SUSE-SU-2016:1177-1 |
| SLES for SAP 12 SP1 | yast2-ntp-client | 3.1.22-6.2 | SUSE-SU-2016:1177-1 |
| 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 | 4.2.8p6-8.2 | SUSE-SU-2016:1278-1, SUSE-SU-2016:1175-1 |
| 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 | 4.2.6p5-25.0.1.el7 | ELSA-2016-2583 |
Advisories 17
- RHSA-2016:2583 Red Hat Security Advisory: ntp security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DLA-559-1 ntp - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3629-1 ntp - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-3096-1 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-2016:1177-1 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-2016:1175-1 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-21-103-11 Siemens TIM 4R-IE Devices CISA ICS & IT advisories · Jun 10, 2025
- SSA-497656 SSA-497656: Multiple NTP Vulnerabilities in TIM 4R-IE Devices Siemens ProductCERT · Jun 10, 2025
- VDE-2022-032 AUMA: Multiple Vulnerabilities in Automation Runtime NTP Service CERT@VDE · Aug 9, 2022
- ELSA-2016-2583 Moderate: ntp security and bug fix update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Nov 9, 2016
References
- http://www.talosintel.com/reports/TALOS-2016-0071/
- DSA-3629 vendor-advisory
- 81960 vdb-entry
- https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03766en_us
- http://support.ntp.org/bin/view/Main/NtpBug2936
- 1034782 vdb-entry
- https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03750en_us
- RHSA-2016:2583 vendor-advisory
- https://security.netapp.com/advisory/ntap-20171031-0001/
- http://bugs.ntp.org/show_bug.cgi?id=2936
- FreeBSD-SA-16:09 vendor-advisory
- GLSA-201607-15 vendor-advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-497656.pdf
- https://us-cert.cisa.gov/ics/advisories/icsa-21-103-11