Description
NTP before 4.2.8p6 and 4.3.0 before 4.3.90 allows a remote attackers to cause a denial of service (stack exhaustion) via an ntpdc relist command, which triggers recursive traversal of the restriction list.
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 |
| RHEL 6 | ntp +3 | 4.2.6p5-10.el6 | RHSA-2016:0780 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP1 | ntp | 4.2.8p6-8.2 | 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-2016:1247-1 |
| 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-2016:1175-1 |
| SLES 11 SP3 | ntp | 4.2.8p6-41.1 | SUSE-SU-2016:1311-1 |
| SLES 11 SP2 | ntp | 4.2.8p6-41.1 | 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-2016:1177-1 |
| 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-2016:1247-1 |
| 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-2016:1175-1 |
| SUSE OpenStack Cloud 5 | ntp | 4.2.8p6-41.1 | SUSE-SU-2016:1311-1 |
| SUSE Manager Proxy 2.1 | ntp | 4.2.8p6-41.1 | SUSE-SU-2016:1311-1 |
| SUSE Manager 2.1 | ntp | 4.2.8p6-41.1 | 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 12
- RHSA-2016:2583 Red Hat Security Advisory: ntp security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2016:0780 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-2016:1175-1 Security update for ntp SUSE / openSUSE Security Updates · Feb 4, 2026
- 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
- 20160120 Multiple Vulnerabilities in Network Time Protocol Daemon Affecting Cisco Products - January 2016 vendor-advisory
- USN-3096-1 vendor-advisory
- SUSE-SU-2016:1177 vendor-advisory
- DSA-3629 vendor-advisory
- http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html
- SUSE-SU-2016:1912 vendor-advisory
- 1034782 vdb-entry
- openSUSE-SU-2016:1292 vendor-advisory
- VU#718152 third-party-advisory
- SUSE-SU-2016:1247 vendor-advisory
- FEDORA-2016-8bb1932088 vendor-advisory
- RHSA-2016:2583 vendor-advisory
- https://security.netapp.com/advisory/ntap-20171031-0001/
- SUSE-SU-2016:1311 vendor-advisory
- RHSA-2016:0780 vendor-advisory
- http://support.ntp.org/bin/view/Main/SecurityNotice#April_2016_NTP_4_2_8p7_Security
- FEDORA-2016-34bc10a2c8 vendor-advisory
- SUSE-SU-2016:2094 vendor-advisory
- 81962 vdb-entry
- SUSE-SU-2016:1175 vendor-advisory
- FreeBSD-SA-16:09 vendor-advisory
- https://bto.bluecoat.com/security-advisory/sa113
- openSUSE-SU-2016:1423 vendor-advisory
- GLSA-201607-15 vendor-advisory