NTP before 4.2.8p9 does not properly perform the initial sync calculations, which allows…
Priority LOW 36CWE-682Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat.
Summary
NTP before 4.2.8p9 does not properly perform the initial sync calculations, which allows remote attackers to unspecified impact via unknown vectors, related to a "root distance that did not include the peer dispersion."
Why it matters now
EPSS 0.09762 95th percentileScored 2026-11-07
Fix Fixed Red Hat: 1 advisory
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 · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:ntp:ntp:*:p8:*:*:*:*:*:* | up to 4.2.8 | Vulnerable | NTP Project |
- cpe:2.3:a:ntp:ntp:*:p8:*:*:*:*:*:* Versions up to 4.2.8 Vulnerable ·NTP Project
Remediation
Red Hat 1 advisory
- RHSA-2017:0252 Released 2017-02-06 · Red Hat rating Moderatentp security update
- Red Hat Enterprise Linux Client (v. 7) ntp-4.2.6p5-25.el7_3.1, ntpdate-4.2.6p5-25.el7_3.1
- Red Hat Enterprise Linux Client Optional (v. 7) ntp-doc-4.2.6p5-25.el7_3.1, ntp-perl-4.2.6p5-25.el7_3.1, sntp-4.2.6p5-25.el7_3.1
- Red Hat Enterprise Linux ComputeNode (v. 7) ntp-4.2.6p5-25.el7_3.1, ntpdate-4.2.6p5-25.el7_3.1
- Red Hat Enterprise Linux ComputeNode Optional (v. 7) ntp-doc-4.2.6p5-25.el7_3.1, ntp-perl-4.2.6p5-25.el7_3.1, sntp-4.2.6p5-25.el7_3.1
- Red Hat Enterprise Linux Desktop (v. 6) ntp-4.2.6p5-10.el6_8.2, ntpdate-4.2.6p5-10.el6_8.2
- Red Hat Enterprise Linux Desktop Optional (v. 6) ntp-doc-4.2.6p5-10.el6_8.2, ntp-perl-4.2.6p5-10.el6_8.2
- Red Hat Enterprise Linux HPC Node (v. 6) ntp-4.2.6p5-10.el6_8.2, ntpdate-4.2.6p5-10.el6_8.2
- Red Hat Enterprise Linux HPC Node Optional (v. 6) ntp-doc-4.2.6p5-10.el6_8.2, ntp-perl-4.2.6p5-10.el6_8.2
- Red Hat Enterprise Linux Server (v. 6) ntp-4.2.6p5-10.el6_8.2, ntpdate-4.2.6p5-10.el6_8.2
- Red Hat Enterprise Linux Server (v. 7) ntp-4.2.6p5-25.el7_3.1, ntpdate-4.2.6p5-25.el7_3.1
- Red Hat Enterprise Linux Server Optional (v. 6) ntp-doc-4.2.6p5-10.el6_8.2, ntp-perl-4.2.6p5-10.el6_8.2
- Red Hat Enterprise Linux Server Optional (v. 7) ntp-doc-4.2.6p5-25.el7_3.1, ntp-perl-4.2.6p5-25.el7_3.1, sntp-4.2.6p5-25.el7_3.1
- Red Hat Enterprise Linux Workstation (v. 6) ntp-4.2.6p5-10.el6_8.2, ntpdate-4.2.6p5-10.el6_8.2
- Red Hat Enterprise Linux Workstation (v. 7) ntp-4.2.6p5-25.el7_3.1, ntpdate-4.2.6p5-25.el7_3.1
- Red Hat Enterprise Linux Workstation Optional (v. 6) ntp-doc-4.2.6p5-10.el6_8.2, ntp-perl-4.2.6p5-10.el6_8.2
- Red Hat Enterprise Linux Workstation Optional (v. 7) ntp-doc-4.2.6p5-25.el7_3.1, ntp-perl-4.2.6p5-25.el7_3.1, sntp-4.2.6p5-25.el7_3.1
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux Client (v. 7) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux Client Optional (v. 7) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux ComputeNode (v. 7) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux ComputeNode Optional (v. 7) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux Desktop (v. 6) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux Desktop Optional (v. 6) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux HPC Node (v. 6) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux HPC Node Optional (v. 6) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux Server (v. 6) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux Server (v. 7) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux Server Optional (v. 6) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux Server Optional (v. 7) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux Workstation (v. 6) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux Workstation (v. 7) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux Workstation Optional (v. 6) | Fixed | RHSA-2017:0252 |
| Red Hat Enterprise Linux Workstation Optional (v. 7) | Fixed | RHSA-2017:0252 |
Not affected: 1 product
- Red Hat Enterprise Linux 5
Timeline
- 2026-10-02 Threatist record created from CVE-2016-7433
- 2026-10-03 Alias added: GHSA-5x79-wfvw-985r
References
Advisory 11
Other 8
- https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03706en_us
- http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
- https://bto.bluecoat.com/security-advisory/sa139
- http://www.huawei.com/en/psirt/security-advisories/huawei-sa-20171129-01-ntpd-en
- https://www.broadcom.com/support/fibre-channel-networking/security-advisories/brocade-security-advisory-2017-227/
- https://www.broadcom.com/support/fibre-channel-networking/security-advisories/brocade-security-advisory-2017-227
- https://cert-portal.siemens.com/productcert/pdf/ssa-211752.pdf
- https://us-cert.cisa.gov/ics/advisories/icsa-21-159-11
More NTP Project Ntp vulnerabilities
- TI-2015-06541 Crypto-NAK packets in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows… CVSS 3.1CRITICAL 9.8
- TI-2014-07543 Multiple stack-based buffer overflows in ntpd in NTP before 4.2.8 allow remote attackers… CVSS 2.0HIGH 7.5
- TI-2013-04524 The monlist feature in ntp_request.c in ntpd in NTP before 4.2.7p26 allows remote… CVSS 2.0MEDIUM 5.0
- TI-2016-06333 The read_mru_list function in NTP before 4.2.8p9 allows remote attackers to cause a… CVSS 3.1HIGH 7.5
- TI-2018-08842 Stack-based buffer overflow in ntpq and ntpdc of NTP version 4.2.8p11 allows an attacker… CVSS 3.0CRITICAL 9.8
- TI-2016-04280 ntpd in NTP before 4.2.8p8 allows remote attackers to cause a denial of service (daemon… CVSS 3.1HIGH 7.5
Sources
- CVE-2016-7433 · CVE Program
- CVE-2016-7433 · NVD
- FIRST EPSS
- GHSA-5x79-wfvw-985r · GitHub Advisory Database · CC BY 4.0
- CVE-2016-7433 · Red Hat security data · CC BY 4.0
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