HIGH
ntp: disabling synchronization via crafted KoD packet
Published Aug 7, 2017
7.5
HIGHCVSS 3.1
EPSS 10.95%
Description
The ntpd client in NTP 4.x before 4.2.8p4 and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service via a number of crafted "KOD" messages.
Affected products
No data.
Configuration 1
OR
- ≥ 4.2.0 · < 4.2.8
- ≥ 4.3.0 · < 4.3.77
- 4.2.8
- 4.2.8
- 4.2.8
- 4.2.8
- 4.2.8
- 4.2.8
- 4.2.8
- 4.2.8
- 4.2.8
- 4.2.8
- 4.2.8
- 4.2.8
- 4.2.8
- 4.2.8
- 4.2.8
- 4.2.8
- 4.2.8
Configuration 2
OR
- 7.0
- 8.0
- 9.0
Configuration 3
OR
- n/a
- n/a
- n/a
- n/a
Configuration 4
OR
- 6.0
- 7.0
- 6.0
- 7.0
- 6.5
- 6.6
- 7.3
- 7.4
- 7.6
- 7.7
- 6.5
- 6.6
- 6.7
- 7.1
- 7.3
- 7.4
- 7.5
- 7.6
- 7.7
- 6.5
- 6.6
- 7.3
- 7.6
- 7.7
- 6.0
- 7.0
Configuration 5
OR
- < 10.4.0
- ≥ 11.0.0 · < 11.2.0
No data.
Red Hat Enterprise Linux 6
ntp-0:4.2.6p5-5.el6_7.2
Fixed · RHSA-2015:1930
Red Hat Enterprise Linux 6.5 Extended Update Support
ntp-0:4.2.6p5-2.el6_5.1
Fixed · RHSA-2015:2520
Red Hat Enterprise Linux 6.6 Extended Update Support
ntp-0:4.2.6p5-3.el6_6.1
Fixed · RHSA-2015:2520
Red Hat Enterprise Linux 7
ntp-0:4.2.6p5-19.ael7b_1.3
Fixed · RHSA-2015:1930
Red Hat Enterprise Linux 5
ntp
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 6 | ntp-0:4.2.6p5-5.el6_7.2 | Fixed | RHSA-2015:1930 |
| Red Hat Enterprise Linux 6.5 Extended Update Support | ntp-0:4.2.6p5-2.el6_5.1 | Fixed | RHSA-2015:2520 |
| Red Hat Enterprise Linux 6.6 Extended Update Support | ntp-0:4.2.6p5-3.el6_6.1 | Fixed | RHSA-2015:2520 |
| Red Hat Enterprise Linux 7 | ntp-0:4.2.6p5-19.ael7b_1.3 | Fixed | RHSA-2015:1930 |
| Red Hat Enterprise Linux 5 | ntp | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This issue did not affect the versions of ntp as shipped with Red Hat Enterprise Linux 5 and Red Hat Enterprise Linux 6.4, as they do not include support for KoD packets.
Metrics
No CVSS v4.0 score for this CVE.
7.5 HIGH NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Impact None
Integrity Impact None
Availability Impact High
No CVSS v3.0 score for this CVE.
5.0 MEDIUM NVD
AV:N/AC:L/Au:N/C:N/I:N/A:P
Access Vector Network
Access Complexity Low
Authentication None
Confidentiality Impact None
Integrity Impact None
Availability Impact Partial
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
10.95% 0.10950
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
EPSS probability 0.10950
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (28 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 10.95% (0.10950) | 95.76th | v5 (v2026.06.15) |
| Jun 15, 2026 | 10.95% (0.10950) | 95.31th | v5 (v2026.06.15) |
| May 21, 2026 | 21.46% (0.21462) | 95.79th | v4 (v2025.03.14) |
| Jan 29, 2026 | 13.94% (0.13941) | 94.13th | v4 (v2025.03.14) |
| Dec 27, 2025 | 7.60% (0.07595) | 91.57th | v4 (v2025.03.14) |
| Dec 13, 2025 | 9.45% (0.09450) | 92.52th | v4 (v2025.03.14) |
| Dec 1, 2025 | 7.60% (0.07595) | 91.52th | v4 (v2025.03.14) |
| Nov 17, 2025 | 19.52% (0.19520) | 95.16th | v4 (v2025.03.14) |
| Sep 16, 2025 | 22.61% (0.22612) | 95.65th | v4 (v2025.03.14) |
| Aug 10, 2025 | 53.09% (0.53087) | 97.85th | v4 (v2025.03.14) |
| Jun 25, 2025 | 57.04% (0.57035) | 97.99th | v4 (v2025.03.14) |
| Mar 30, 2025 | 52.02% (0.52020) | 97.69th | v4 (v2025.03.14) |
| Mar 29, 2025 | 54.98% (0.54980) | 97.17th | v4 (v2025.03.14) |
| Mar 21, 2025 | 52.02% (0.52020) | 97.72th | v4 (v2025.03.14) |
| Mar 17, 2025 | 43.67% (0.43673) | 97.22th | v4 (v2025.03.14) |
| Dec 17, 2024 | 90.36% (0.90364) | 99.07th | v3 (v2023.03.01) |
| Nov 7, 2024 | 81.93% (0.81926) | 98.47th | v3 (v2023.03.01) |
| Jul 10, 2024 | 83.23% (0.83230) | 98.47th | v3 (v2023.03.01) |
| May 28, 2024 | 86.03% (0.86032) | 98.56th | v3 (v2023.03.01) |
| Mar 10, 2024 | 87.35% (0.87346) | 98.54th | v3 (v2023.03.01) |
| Feb 1, 2024 | 87.92% (0.87917) | 98.43th | v3 (v2023.03.01) |
| Dec 23, 2023 | 89.54% (0.89536) | 98.50th | v3 (v2023.03.01) |
| Nov 11, 2023 | 89.94% (0.89938) | 98.48th | v3 (v2023.03.01) |
| Jun 17, 2023 | 90.86% (0.90861) | 98.36th | v3 (v2023.03.01) |
| Mar 7, 2023 | 91.80% (0.91803) | 98.31th | v3 (v2023.03.01) |
| Mar 6, 2023 | 4.36% (0.04358) | 88.02th | v2 (v2022.01.01) |
| Apr 1, 2022 | 4.36% (0.04358) | 86.83th | v2 (v2022.01.01) |
| Feb 4, 2022 | 4.36% (0.04358) | 70.59th | v2 (v2022.01.01) |
Weaknesses (1)
References (23)
- http://bugs.ntp.org/show_bug.cgi?id=2901 x_refsource_CONFIRMIssue TrackingVendor Advisory
- http://rhn.redhat.com/errata/RHSA-2015-1930.html vendor-advisoryx_refsource_REDHATThird Party Advisory
- http://rhn.redhat.com/errata/RHSA-2015-2520.html vendor-advisoryx_refsource_REDHATThird Party Advisory
- http://support.ntp.org/bin/view/Main/NtpBug2901 x_refsource_CONFIRMVendor Advisory
- http://support.ntp.org/bin/view/Main/SecurityNotice#October_2015_NTP_4_2_8p4_Securit x_refsource_CONFIRMRelease NotesVendor Advisory
- http://www.debian.org/security/2015/dsa-3388 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html x_refsource_CONFIRMThird Party Advisory
- http://www.securityfocus.com/bid/77280 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1033951 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- https://access.redhat.com/security/cve/CVE-2015-7704 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1271070 x_refsource_CONFIRMIssue TrackingThird Party AdvisoryVDB Entry
- https://eprint.iacr.org/2015/1020.pdf x_refsource_MISCTechnical DescriptionThird Party Advisory
- https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05270839 x_refsource_CONFIRMThird Party AdvisoryVDB Entry
- https://kc.mcafee.com/corporate/index?page=content&id=SB10284 x_refsource_CONFIRMThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2015-7704
- https://security.gentoo.org/glsa/201607-15 vendor-advisoryx_refsource_GENTOOThird Party AdvisoryVDB Entry
- https://security.netapp.com/advisory/ntap-20171004-0001/ x_refsource_CONFIRMThird Party Advisory
- https://security.netapp.com/advisory/ntap-20171004-0002/ x_refsource_CONFIRMThird Party Advisory
- https://support.citrix.com/article/CTX220112 x_refsource_CONFIRMThird Party Advisory
- https://www.arista.com/en/support/advisories-notices/security-advisories/1212-security-advisory-0016 x_refsource_MISC
- https://www.cs.bu.edu/~goldbe/NTPattack.html x_refsource_MISCThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2015-7704
- https://www.kb.cert.org/vuls/id/718152 third-party-advisoryx_refsource_CERT-VNThird Party AdvisoryUS Government Resource
Change history (0)
No recorded changes yet.
Sources
CVE.org / MITRE
Status PUBLISHED
Assigner mitre
Published Aug 7, 2017
Updated Aug 6, 2024
Reserved Oct 4, 2015
Link CVE-2015-7704
CISA Vulnrichment
Updated n/a