The read_network_packet function in ntp_io.c in ntpd in NTP 4.x before 4.2.8p1 on Linux…
Priority LOW 37CWE-20Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- — Not recorded in CVSS 2.0
- Attack complexity
- Medium
- Impact type
- —
- Confidentiality · integrity · availability
- Partial · Partial · Partial
- Fix status
- Partial Red Hat: 16 fixed, 1 without a fix
Attack profile from CVSS 2.0 · NVD. Fix status from CNA and Red Hat.
Summary
The read_network_packet function in ntp_io.c in ntpd in NTP 4.x before 4.2.8p1 on Linux and OS X does not properly determine whether a source IP address is an IPv6 loopback address, which makes it easier for remote attackers to spoof restricted packets, and read or write to the runtime state, by leveraging the ability to reach the ntpd machine's network interface with a packet from the ::1 address.
Why it matters now
EPSS 0.04532 91st percentileScored 2026-11-07
Fix Partial Red Hat: 2 advisoriesRed Hat: 16 fixed, 1 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 11
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:ntp:ntp:*:*:*:*:*:*:*:* | 4.2.0 to before 4.2.8 | Vulnerable | NTP Project |
| cpe:2.3:a:ntp:ntp:4.2.8:-:*:*:*:*:*:* | 4.2.8 | Vulnerable | NTP Project |
| cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Apple |
| cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Linux |
| cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:* | 6.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:* | 6.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:* | 6.0 | Vulnerable | Red Hat |
| cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
- cpe:2.3:a:ntp:ntp:*:*:*:*:*:*:*:* Versions 4.2.0 to before 4.2.8 Vulnerable ·NTP Project
- cpe:2.3:a:ntp:ntp:4.2.8:-:*:*:*:*:*:* Versions 4.2.8 Vulnerable ·NTP Project
- cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Apple
- cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Linux
- cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:* Versions 6.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:* Versions 6.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:* Versions 6.0 Vulnerable ·Red Hat
- cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
Remediation
Red Hat 2 advisories
- RHSA-2015:2231 Released 2015-11-19 · Red Hat rating Moderatentp security, bug fix, and enhancement update
- Red Hat Enterprise Linux Client (v. 7) ntp-4.2.6p5-22.el7, ntpdate-4.2.6p5-22.el7
- Red Hat Enterprise Linux Client Optional (v. 7) ntp-doc-4.2.6p5-22.el7, ntp-perl-4.2.6p5-22.el7, sntp-4.2.6p5-22.el7
- Red Hat Enterprise Linux ComputeNode (v. 7) ntp-4.2.6p5-22.el7, ntpdate-4.2.6p5-22.el7
- Red Hat Enterprise Linux ComputeNode Optional (v. 7) ntp-doc-4.2.6p5-22.el7, ntp-perl-4.2.6p5-22.el7, sntp-4.2.6p5-22.el7
- Red Hat Enterprise Linux Server (v. 7) ntp-4.2.6p5-22.el7, ntpdate-4.2.6p5-22.el7
- Red Hat Enterprise Linux Server Optional (v. 7) ntp-doc-4.2.6p5-22.el7, ntp-perl-4.2.6p5-22.el7, sntp-4.2.6p5-22.el7
- Red Hat Enterprise Linux Workstation (v. 7) ntp-4.2.6p5-22.el7, ntpdate-4.2.6p5-22.el7
- Red Hat Enterprise Linux Workstation Optional (v. 7) ntp-doc-4.2.6p5-22.el7, ntp-perl-4.2.6p5-22.el7, sntp-4.2.6p5-22.el7
- RHSA-2015:1459 Released 2015-07-21 · Red Hat rating Moderatentp security, bug fix, and enhancement update
- Red Hat Enterprise Linux Desktop (v. 6) ntp-4.2.6p5-5.el6, ntpdate-4.2.6p5-5.el6
- Red Hat Enterprise Linux Desktop Optional (v. 6) ntp-doc-4.2.6p5-5.el6, ntp-perl-4.2.6p5-5.el6
- Red Hat Enterprise Linux HPC Node (v. 6) ntp-4.2.6p5-5.el6, ntpdate-4.2.6p5-5.el6
- Red Hat Enterprise Linux HPC Node Optional (v. 6) ntp-doc-4.2.6p5-5.el6, ntp-perl-4.2.6p5-5.el6
- Red Hat Enterprise Linux Server (v. 6) ntp-4.2.6p5-5.el6, ntpdate-4.2.6p5-5.el6
- Red Hat Enterprise Linux Server Optional (v. 6) ntp-doc-4.2.6p5-5.el6, ntp-perl-4.2.6p5-5.el6
- Red Hat Enterprise Linux Workstation (v. 6) ntp-4.2.6p5-5.el6, ntpdate-4.2.6p5-5.el6
- Red Hat Enterprise Linux Workstation Optional (v. 6) ntp-doc-4.2.6p5-5.el6, ntp-perl-4.2.6p5-5.el6
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux Client (v. 7) | Fixed | RHSA-2015:2231 |
| Red Hat Enterprise Linux Client Optional (v. 7) | Fixed | RHSA-2015:2231 |
| Red Hat Enterprise Linux ComputeNode (v. 7) | Fixed | RHSA-2015:2231 |
| Red Hat Enterprise Linux ComputeNode Optional (v. 7) | Fixed | RHSA-2015:2231 |
| Red Hat Enterprise Linux Desktop (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux Desktop Optional (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux HPC Node (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux HPC Node Optional (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux Server (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux Server (v. 7) | Fixed | RHSA-2015:2231 |
| Red Hat Enterprise Linux Server Optional (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux Server Optional (v. 7) | Fixed | RHSA-2015:2231 |
| Red Hat Enterprise Linux Workstation (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux Workstation (v. 7) | Fixed | RHSA-2015:2231 |
| Red Hat Enterprise Linux Workstation Optional (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux Workstation Optional (v. 7) | Fixed | RHSA-2015:2231 |
Timeline
- 2026-10-02 Threatist record created from CVE-2014-9751
- 2026-10-03 Alias added: GHSA-ffj6-rf7h-c479
References
Advisory 7
- VU#852879
- http://support.ntp.org/bin/view/Main/SecurityNotice#December_2014_NTP_Security_Vulne
- http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
- DSA-3388
- RHSA-2015:1459
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03886en_us
- https://bugzilla.redhat.com/show_bug.cgi?id=1184572
Sources
- CVE-2014-9751 · CVE Program
- CVE-2014-9751 · NVD
- FIRST EPSS
- GHSA-ffj6-rf7h-c479 · GitHub Advisory Database · CC BY 4.0
- CVE-2014-9751 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences