ntp: slow memory leak in CRYPTO_ASSOC
Published Aug 7, 2017
7.5
HIGHCVSS 3.1
EPSS 6.52%
Description
Memory leak in the CRYPTO_ASSOC function in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service (memory consumption).
Affected products
No data.
Configuration 1
- ≥ 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 3
- 7.0
- 8.0
- 9.0
Configuration 4
- n/a
- n/a
- n/a
- n/a
Configuration 5
- 6.0
- 7.0
- 6.0
- 7.0
- 7.3
- 7.4
- 7.6
- 7.7
- 7.3
- 7.4
- 7.5
- 7.6
- 7.7
- 7.3
- 7.6
- 7.7
- 6.0
- 7.0
No data.
Red Hat Enterprise Linux 6
ntp-0:4.2.6p5-10.el6
Fixed · RHSA-2016:0780
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
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 6 | ntp-0:4.2.6p5-10.el6 | Fixed | RHSA-2016:0780 |
| 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 |
No package ranges for this CVE.
Remediation
Red Hat mitigation
Disable NTP autokey authentication by removing, or commenting out, all configuration directives beginning with the 'crypto' keyword in your ntp.conf file.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
No CVSS v3.0 score for this CVE.
AV:N/AC:L/Au:N/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
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (27 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 6.52% (0.06519) | 93.57th | v5 (v2026.06.15) |
| Jun 15, 2026 | 6.52% (0.06519) | 92.88th | v5 (v2026.06.15) |
| May 27, 2026 | 11.21% (0.11211) | 93.61th | v4 (v2025.03.14) |
| May 25, 2026 | 12.99% (0.12986) | 94.17th | v4 (v2025.03.14) |
| May 21, 2026 | 11.21% (0.11211) | 93.60th | v4 (v2025.03.14) |
| May 18, 2026 | 12.41% (0.12406) | 93.97th | v4 (v2025.03.14) |
| May 13, 2026 | 14.33% (0.14332) | 94.47th | v4 (v2025.03.14) |
| Jan 18, 2026 | 12.41% (0.12406) | 93.68th | v4 (v2025.03.14) |
| Dec 28, 2025 | 15.96% (0.15961) | 94.54th | v4 (v2025.03.14) |
| Dec 27, 2025 | 7.80% (0.07797) | 91.70th | v4 (v2025.03.14) |
| Dec 16, 2025 | 15.96% (0.15961) | 94.53th | v4 (v2025.03.14) |
| Dec 14, 2025 | 12.88% (0.12880) | 93.79th | v4 (v2025.03.14) |
| Dec 13, 2025 | 10.84% (0.10842) | 93.11th | v4 (v2025.03.14) |
| Aug 10, 2025 | 7.80% (0.07797) | 91.56th | v4 (v2025.03.14) |
| Jun 25, 2025 | 6.32% (0.06317) | 90.49th | v4 (v2025.03.14) |
| Mar 30, 2025 | 3.65% (0.03655) | 86.77th | v4 (v2025.03.14) |
| Mar 29, 2025 | 10.16% (0.10161) | 88.44th | v4 (v2025.03.14) |
| Mar 17, 2025 | 3.06% (0.03063) | 85.81th | v4 (v2025.03.14) |
| Dec 17, 2024 | 23.12% (0.23121) | 96.56th | v3 (v2023.03.01) |
| Nov 7, 2024 | 6.92% (0.06918) | 94.12th | v3 (v2023.03.01) |
| Jul 10, 2024 | 5.31% (0.05311) | 93.13th | v3 (v2023.03.01) |
| May 28, 2024 | 5.00% (0.05005) | 92.84th | v3 (v2023.03.01) |
| Nov 11, 2023 | 4.50% (0.04499) | 91.55th | v3 (v2023.03.01) |
| Mar 7, 2023 | 6.23% (0.06234) | 92.43th | v3 (v2023.03.01) |
| Mar 6, 2023 | 2.17% (0.02172) | 80.77th | v2 (v2022.01.01) |
| Apr 1, 2022 | 2.17% (0.02172) | 78.91th | v2 (v2022.01.01) |
| Feb 4, 2022 | 2.17% (0.02172) | 57.73th | v2 (v2022.01.01) |
References (15)
- http://rhn.redhat.com/errata/RHSA-2016-0780.html vendor-advisoryx_refsource_REDHATThird Party Advisory
- http://rhn.redhat.com/errata/RHSA-2016-2583.html vendor-advisoryx_refsource_REDHATThird Party Advisory
- http://support.ntp.org/bin/view/Main/NtpBug2909 x_refsource_CONFIRMVendor Advisory
- http://support.ntp.org/bin/view/Main/SecurityNotice#October_2015_NTP_Security_Vulner
- http://www.debian.org/security/2015/dsa-3388 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html x_refsource_CONFIRMThird Party Advisory
- http://www.securityfocus.com/bid/77281 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-2015-7701 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1274255 x_refsource_CONFIRMIssue TrackingThird Party AdvisoryVDB Entry
- https://github.com/ntp-project/ntp/blob/stable/NEWS#L91
- https://nvd.nist.gov/vuln/detail/CVE-2015-7701
- 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://www.cve.org/CVERecord?id=CVE-2015-7701
Change history (0)
No recorded changes yet.