ntp: Denial of Service via Malformed Config
Published Mar 27, 2017
6.5
MEDIUMCVSS 3.0
EPSS 5.10%
Description
NTP before 4.2.8p10 and 4.3.x before 4.3.94 allows remote attackers to cause a denial of service (ntpd crash) via a malformed mode configuration directive.
Affected products
No data.
- 4.2.8
- 4.3.0
- 4.3.1
- 4.3.2
- 4.3.3
- 4.3.4
- 4.3.5
- 4.3.6
- 4.3.7
- 4.3.8
- 4.3.9
- 4.3.10
- 4.3.11
- 4.3.12
- 4.3.13
- 4.3.14
- 4.3.15
- 4.3.16
- 4.3.17
- 4.3.18
- 4.3.19
- 4.3.20
- 4.3.21
- 4.3.22
- 4.3.23
- 4.3.24
- 4.3.25
- 4.3.26
- 4.3.27
- 4.3.28
- 4.3.29
- 4.3.30
- 4.3.31
- 4.3.32
- 4.3.33
- 4.3.34
- 4.3.35
- 4.3.36
- 4.3.37
- 4.3.38
- 4.3.39
- 4.3.40
- 4.3.41
- 4.3.42
- 4.3.43
- 4.3.44
- 4.3.45
- 4.3.46
- 4.3.47
- 4.3.48
- 4.3.49
- 4.3.50
- 4.3.51
- 4.3.52
- 4.3.53
- 4.3.54
- 4.3.55
- 4.3.56
- 4.3.57
- 4.3.58
- 4.3.59
- 4.3.60
- 4.3.61
- 4.3.62
- 4.3.63
- 4.3.64
- 4.3.65
- 4.3.66
- 4.3.67
- 4.3.68
- 4.3.69
- 4.3.70
- 4.3.71
- 4.3.72
- 4.3.73
- 4.3.74
- 4.3.75
- 4.3.76
- 4.3.77
- 4.3.78
- 4.3.79
- 4.3.80
- 4.3.81
- 4.3.82
- 4.3.83
- 4.3.84
- 4.3.85
- 4.3.86
- 4.3.87
- 4.3.88
- 4.3.89
- 4.3.90
- 4.3.91
- 4.3.92
- 4.3.93
No data.
Red Hat Enterprise Linux 6
ntp-0:4.2.6p5-12.el6_9.1
Fixed · RHSA-2017:3071
Red Hat Enterprise Linux 7
ntp-0:4.2.6p5-28.el7
Fixed · RHSA-2018:0855
Red Hat Enterprise Linux 5
ntp
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 6 | ntp-0:4.2.6p5-12.el6_9.1 | Fixed | RHSA-2017:3071 |
| Red Hat Enterprise Linux 7 | ntp-0:4.2.6p5-28.el7 | Fixed | RHSA-2018:0855 |
| Red Hat Enterprise Linux 5 | ntp | Will not fix | n/a |
No package ranges for this CVE.
Remediation
Red Hat mitigation
Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
1 other source (Red Hat) ▾
CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
AV:N/AC:L/Au:S/C:N/I:N/A:P
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (17 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 5.10% (0.05103) | 92.11th | v5 (v2026.06.15) |
| Jun 15, 2026 | 5.15% (0.05145) | 91.31th | v5 (v2026.06.15) |
| May 4, 2026 | 3.56% (0.03560) | 87.75th | v4 (v2025.03.14) |
| Mar 29, 2025 | 2.10% (0.02099) | 73.42th | v4 (v2025.03.14) |
| Mar 17, 2025 | 3.13% (0.03125) | 85.96th | v4 (v2025.03.14) |
| Dec 17, 2024 | 7.25% (0.07252) | 93.98th | v3 (v2023.03.01) |
| Feb 28, 2024 | 8.88% (0.08885) | 94.40th | v3 (v2023.03.01) |
| Jan 16, 2024 | 8.40% (0.08397) | 93.79th | v3 (v2023.03.01) |
| Mar 7, 2023 | 7.58% (0.07582) | 93.07th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.65% (0.01649) | 75.99th | v2 (v2022.01.01) |
| Feb 23, 2023 | 1.65% (0.01649) | 75.95th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.65% (0.01649) | 73.90th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.65% (0.01649) | 52.77th | v2 (v2022.01.01) |
| Feb 3, 2022 | 3.21% (0.03209) | 66.48th | v1 |
| Jan 6, 2022 | 3.21% (0.03209) | 66.16th | v1 |
| Sep 1, 2021 | 3.21% (0.03209) | 81.46th | v1 |
| Apr 14, 2021 | 3.21% (0.03209) | 0.00th | v1 |
References (13)
- http://support.ntp.org/bin/view/Main/NtpBug3389 x_refsource_CONFIRMPatchVendor Advisory
- http://support.ntp.org/bin/view/Main/SecurityNotice#March_2017_ntp_4_2_8p10_NTP_Secu x_refsource_CONFIRMVendor Advisory
- http://www.securityfocus.com/bid/97050 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1038123 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- https://access.redhat.com/errata/RHSA-2017:3071 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2018:0855 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2017-6464 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1433987 Issue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2017-6464
- https://security.FreeBSD.org/advisories/FreeBSD-SA-17:03.ntp.asc vendor-advisoryx_refsource_FREEBSD
- https://support.apple.com/HT208144 x_refsource_CONFIRM
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03962en_us x_refsource_CONFIRM
- https://www.cve.org/CVERecord?id=CVE-2017-6464
Change history (0)
No recorded changes yet.