CVE catalog
CVE-2016-4955
UBUNTU-CVE-2016-4955
- Severity
- Medium · CVSS 5.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Updated
- Source
- [NVD] · [CVE record]
- EPSS
- 8.77% · Oct 25, 2026
ntpd in NTP 4.x before 4.2.8p8, when autokey is enabled, allows remote attackers to cause a denial of service (peer-variable clearing and association outage) by sending (1) a spoofed crypto-NAK packet or (2) a packet with an incorrect MAC value at a certain time.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | ntp | 11 | 1:4.2.8p8+dfsg-1 | fixed |
| Ubuntu | ntp | 14.04 | 1:4.2.6.p5+dfsg-3ubuntu2 | vulnerable |
| Ubuntu | ntp | 14.04 | 1:4.2.6.p5+dfsg-3ubuntu2.14.04.1 | vulnerable |
| Ubuntu | ntp | 14.04 | 1:4.2.6.p5+dfsg-3ubuntu2.14.04.2 | vulnerable |
| Ubuntu | ntp | 14.04 | 1:4.2.6.p5+dfsg-3ubuntu2.14.04.3 | vulnerable |
| Ubuntu | ntp | 14.04 | 1:4.2.6.p5+dfsg-3ubuntu2.14.04.5 | vulnerable |
| Ubuntu | ntp | 14.04 | 1:4.2.6.p5+dfsg-3ubuntu2.14.04.6 | vulnerable |
| Ubuntu | ntp | 14.04 | 1:4.2.6.p5+dfsg-3ubuntu2.14.04.7 | vulnerable |
| Ubuntu | ntp | 14.04 | 1:4.2.6.p5+dfsg-3ubuntu2.14.04.8 | vulnerable |
| Ubuntu | ntp | 14.04 | 1:4.2.6.p5+dfsg-3ubuntu2.14.04.10 | fixed |
| Ubuntu | ntp | 16.04 | 1:4.2.6.p5+dfsg-3ubuntu8 | vulnerable |
| Ubuntu | ntp | 16.04 | 1:4.2.6.p5+dfsg-3ubuntu8.1 | vulnerable |
| Ubuntu | ntp | 16.04 | 1:4.2.6.p5+dfsg-3ubuntu9 | vulnerable |
| Ubuntu | ntp | 16.04 | 1:4.2.8p4+dfsg-3ubuntu1 | vulnerable |
| Ubuntu | ntp | 16.04 | 1:4.2.8p4+dfsg-3ubuntu2 | vulnerable |
| Ubuntu | ntp | 16.04 | 1:4.2.8p4+dfsg-3ubuntu3 | vulnerable |
| Ubuntu | ntp | 16.04 | 1:4.2.8p4+dfsg-3ubuntu4 | vulnerable |
| Ubuntu | ntp | 16.04 | 1:4.2.8p4+dfsg-3ubuntu5 | vulnerable |
| Ubuntu | ntp | 16.04 | 1:4.2.8p4+dfsg-3ubuntu5.1 | vulnerable |
| Ubuntu | ntp | 16.04 | 1:4.2.8p4+dfsg-3ubuntu5.2 | vulnerable |
| Ubuntu | ntp | 16.04 | 1:4.2.8p4+dfsg-3ubuntu5.3 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | ntp | deb | 11 | 1:4.2.8p8+dfsg-1 | Not reported | DEBIAN-CVE-2016-4955 | Not reported |
| Ubuntu | ntp | deb | 14.04 | 1:4.2.6.p5+dfsg-3ubuntu2.14.04.10 | Not reported | UBUNTU-CVE-2016-4955 | Not reported |
| Ubuntu | ntp | deb | 16.04 | 1:4.2.8p4+dfsg-3ubuntu5.3 | Not reported | UBUNTU-CVE-2016-4955 | Not reported |
OpenFactory catalog packages
No matching packages in this catalog.
Observed: