ntp: missing key check allows impersonation between authenticated peers (VU#357792)
Published Jan 26, 2016
7.7
HIGHCVSS 3.1
EPSS 5.66%
Description
NTP 4.x before 4.2.8p6 and 4.3.x before 4.3.90 do not verify peer associations of symmetric keys when authenticating packets, which might allow remote attackers to conduct impersonation attacks via an arbitrary trusted key, aka a "skeleton key."
Affected products
No data.
Configuration 1
- ≥ 4.2.0 · < 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
- n/a
- n/a
Configuration 5
- 8.0
- 9.0
No data.
Red Hat Enterprise Linux 7
ntp-0:4.2.6p5-25.el7
Fixed · RHSA-2016:2583
Red Hat Enterprise Linux 5
ntp
Will not fix
Red Hat Enterprise Linux 6
ntp
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 7 | ntp-0:4.2.6p5-25.el7 | Fixed | RHSA-2016:2583 |
| Red Hat Enterprise Linux 5 | ntp | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | ntp | Will not fix | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
Red Hat Product Security has rated this issue as having Low security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
No CVSS v3.0 score for this CVE.
AV:N/AC:L/Au:S/C:N/I:P/A:N
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 (19 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 5.66% (0.05658) | 92.73th | v5 (v2026.06.15) |
| Jun 15, 2026 | 5.71% (0.05705) | 92.00th | v5 (v2026.06.15) |
| May 4, 2026 | 10.69% (0.10689) | 93.35th | v4 (v2025.03.14) |
| Jan 14, 2026 | 7.48% (0.07477) | 91.50th | v4 (v2025.03.14) |
| Dec 28, 2025 | 5.31% (0.05314) | 89.70th | v4 (v2025.03.14) |
| Dec 27, 2025 | 3.67% (0.03667) | 87.57th | v4 (v2025.03.14) |
| Dec 13, 2025 | 5.93% (0.05931) | 90.29th | v4 (v2025.03.14) |
| Aug 10, 2025 | 3.67% (0.03667) | 87.44th | v4 (v2025.03.14) |
| Jul 7, 2025 | 5.11% (0.05113) | 89.35th | v4 (v2025.03.14) |
| May 6, 2025 | 6.48% (0.06480) | 90.55th | v4 (v2025.03.14) |
| Mar 30, 2025 | 4.18% (0.04182) | 87.64th | v4 (v2025.03.14) |
| Mar 29, 2025 | 8.33% (0.08329) | 86.87th | v4 (v2025.03.14) |
| Mar 17, 2025 | 4.18% (0.04182) | 87.94th | v4 (v2025.03.14) |
| Dec 17, 2024 | 2.18% (0.02181) | 89.03th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.29% (0.00290) | 68.15th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.29% (0.00290) | 64.11th | v3 (v2023.03.01) |
| Mar 6, 2023 | 2.19% (0.02186) | 80.97th | v2 (v2022.01.01) |
| Apr 1, 2022 | 2.19% (0.02186) | 79.16th | v2 (v2022.01.01) |
| Feb 4, 2022 | 2.19% (0.02186) | 57.93th | v2 (v2022.01.01) |
References (18)
- http://bugs.ntp.org/show_bug.cgi?id=2936 x_refsource_CONFIRMIssue TrackingVendor Advisory
- http://rhn.redhat.com/errata/RHSA-2016-2583.html vendor-advisoryx_refsource_REDHATThird Party Advisory
- http://support.ntp.org/bin/view/Main/NtpBug2936 x_refsource_CONFIRMVendor Advisory
- http://www.debian.org/security/2016/dsa-3629 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- http://www.securityfocus.com/bid/81960 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-2016-0071/ x_refsource_MISCExploitThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2015-7974 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1297471 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-2015-7974
- 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_MISCThird Party AdvisoryUS Government Resource
- https://www.cve.org/CVERecord?id=CVE-2015-7974
Change history (0)
No recorded changes yet.