ntp: replay attack on authenticated broadcast mode
Published Jan 30, 2017
6.5
MEDIUMCVSS 3.1
EPSS 3.36%
Description
NTP before 4.2.8p6 and 4.3.x before 4.3.90, when configured in broadcast mode, allows man-in-the-middle attackers to conduct replay attacks by sniffing the network.
Affected products
No data.
Configuration 1
- < 4.2.8
- ≥ 4.3.0 · < 4.3.90
- 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
- 4.2.8
- 4.2.8
Configuration 2
- n/a
Configuration 3
- n/a
Running on/with
- n/a
Configuration 4
- ≥ 10.0 · < 10.1
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 9.3
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.1
- 10.2
- 10.2
- 10.2
- 10.2
- 10.2
- 10.2
- 10.2
- 10.2
Configuration 5
- n/a
- n/a
Configuration 6
- 12.04
- 14.04
- 16.04
No data.
Red Hat Enterprise Linux 5
ntp
Will not fix
Red Hat Enterprise Linux 6
ntp
Will not fix
Red Hat Enterprise Linux 7
ntp
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | ntp | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | ntp | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | ntp | Will not fix | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This issue affects the versions of ntp as shipped with Red Hat Enterprise Linux 5, 6, and 7. Red Hat Product Security has rated this issue as having Moderate security impact. A future update may address this issue in Red Hat Enterprise Linux 6 and 7. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
Red Hat mitigation
Do not use NTP's broadcast mode by not configuring the "broadcast" directive in the ntp.conf file.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
No CVSS v3.0 score for this CVE.
AV:N/AC:M/Au:N/C:N/I:P/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
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- 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 | 3.36% (0.03362) | 88.33th | v5 (v2026.06.15) |
| Jun 15, 2026 | 3.33% (0.03334) | 87.02th | v5 (v2026.06.15) |
| Jan 14, 2026 | 8.60% (0.08603) | 92.16th | v4 (v2025.03.14) |
| Dec 28, 2025 | 5.73% (0.05731) | 90.15th | v4 (v2025.03.14) |
| Dec 27, 2025 | 4.59% (0.04588) | 88.92th | v4 (v2025.03.14) |
| Dec 16, 2025 | 5.73% (0.05731) | 90.10th | v4 (v2025.03.14) |
| Aug 10, 2025 | 4.59% (0.04588) | 88.80th | v4 (v2025.03.14) |
| Mar 30, 2025 | 7.31% (0.07309) | 90.82th | v4 (v2025.03.14) |
| Mar 29, 2025 | 19.44% (0.19438) | 92.46th | v4 (v2025.03.14) |
| Mar 17, 2025 | 7.31% (0.07309) | 91.01th | v4 (v2025.03.14) |
| Dec 17, 2024 | 3.14% (0.03138) | 90.88th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.67% (0.00666) | 79.06th | v3 (v2023.03.01) |
| May 6, 2023 | 0.67% (0.00666) | 76.72th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.66% (0.00657) | 76.33th | v3 (v2023.03.01) |
| Mar 6, 2023 | 2.69% (0.02686) | 82.85th | v2 (v2022.01.01) |
| Apr 1, 2022 | 2.69% (0.02686) | 81.17th | v2 (v2022.01.01) |
| Feb 4, 2022 | 2.69% (0.02686) | 62.66th | v2 (v2022.01.01) |
References (28)
- http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00059.html vendor-advisoryx_refsource_SUSEBroken Link
- http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00060.html vendor-advisoryx_refsource_SUSEBroken Link
- http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00020.html vendor-advisoryx_refsource_SUSEBroken Link
- http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00038.html vendor-advisoryx_refsource_SUSEBroken Link
- http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00048.html vendor-advisoryx_refsource_SUSEBroken Link
- http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00026.html vendor-advisoryx_refsource_SUSEBroken Link
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00042.html vendor-advisoryx_refsource_SUSEBroken Link
- http://lists.opensuse.org/opensuse-updates/2016-05/msg00114.html vendor-advisoryx_refsource_SUSEBroken Link
- http://support.ntp.org/bin/view/Main/NtpBug2935 x_refsource_CONFIRMVendor Advisory
- http://support.ntp.org/bin/view/Main/SecurityNotice#January_2016_NTP_4_2_8p6_Securit
- http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160127-ntpd vendor-advisoryx_refsource_CISCOThird Party Advisory
- http://www.securityfocus.com/bid/81963 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1034782 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- http://www.talosintel.com/reports/TALOS-2016-0070/
- http://www.ubuntu.com/usn/USN-3096-1 vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2015-7973 Vendor Advisory
- https://bto.bluecoat.com/security-advisory/sa113 x_refsource_CONFIRMThird Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1300266 Issue Tracking
- https://cert-portal.siemens.com/productcert/pdf/ssa-497656.pdf x_refsource_CONFIRMThird Party Advisory
- https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03750en_us x_refsource_CONFIRMThird Party Advisory
- https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03766en_us x_refsource_CONFIRMThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2015-7973
- https://security.FreeBSD.org/advisories/FreeBSD-SA-16:09.ntp.asc vendor-advisoryx_refsource_FREEBSDThird Party Advisory
- https://security.gentoo.org/glsa/201607-15 vendor-advisoryx_refsource_GENTOOThird Party Advisory
- https://security.netapp.com/advisory/ntap-20171031-0001/ x_refsource_CONFIRMThird Party Advisory
- https://us-cert.cisa.gov/ics/advisories/icsa-21-103-11 x_refsource_CONFIRMThird Party AdvisoryUS Government Resource
- https://www.cve.org/CVERecord?id=CVE-2015-7973
- 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.