Description
The read_mru_list function in NTP before 4.2.8p9 allows remote attackers to cause a denial of service (crash) via a crafted mrulist query.
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 |
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 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 1
- NTP 4.2.8p8 - Denial of Service EDB-40806 · dos · Nov 21, 2016 · verified
GitHub 3 repositories
-
opsxcq/exploit-CVE-2016-7434 ★ 25 · Nov 22, 2016
NTPD remote DOS exploit and vulnerable container
-
shekkbuilder/CVE-2016-7434 ★ 2 · Nov 27, 2016
-
cved-sources/cve-2016-7434 ★ 0 · Jan 6, 2019
cve-2016-7434
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 7
- 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
References
- https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03706en_us
- 94448 vdb-entry
- http://support.ntp.org/bin/view/Main/NtpBug3082
- 40806 exploit
- http://support.ntp.org/bin/view/Main/SecurityNotice#Recent_Vulnerabilities
- http://nwtime.org/ntp428p9_release/
- VU#633847 third-party-advisory
- 1037354 vdb-entry
- https://bto.bluecoat.com/security-advisory/sa139
- FreeBSD-SA-16:39 vendor-advisory