CRITICAL
ntp: reference clock memory corruption vulnerability
Published Aug 7, 2017
9.8
CRITICALCVSS 3.1
EPSS 11.78%
Description
The datalen parameter in the refclock driver in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to execute arbitrary code or cause a denial of service (crash) via a negative input value.
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
- n/a
- n/a
- n/a
- n/a
- n/a
No data.
Red Hat Enterprise Linux 5
ntp
Not affected
Red Hat Enterprise Linux 6
ntp
Not affected
Red Hat Enterprise Linux 7
ntp
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | ntp | Not affected | n/a |
| Red Hat Enterprise Linux 6 | ntp | Not affected | n/a |
| Red Hat Enterprise Linux 7 | 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, 6, and 7 as they do not include the custom refclock driver.
Metrics
No CVSS v4.0 score for this CVE.
9.8 CRITICAL NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Impact High
Integrity Impact High
Availability Impact High
No CVSS v3.0 score for this CVE.
7.5 HIGH NVD
AV:N/AC:L/Au:N/C:P/I:P/A:P
Access Vector Network
Access Complexity Low
Authentication None
Confidentiality Impact Partial
Integrity Impact Partial
Availability Impact Partial
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
11.78% 0.11781
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
EPSS probability 0.11781
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 (22 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 11.78% (0.11781) | 95.96th | v5 (v2026.06.15) |
| Jun 15, 2026 | 11.78% (0.11781) | 95.53th | v5 (v2026.06.15) |
| May 1, 2026 | 40.56% (0.40561) | 97.37th | v4 (v2025.03.14) |
| Dec 28, 2025 | 34.95% (0.34954) | 96.87th | v4 (v2025.03.14) |
| Dec 27, 2025 | 20.96% (0.20956) | 95.48th | v4 (v2025.03.14) |
| Dec 16, 2025 | 34.95% (0.34954) | 96.86th | v4 (v2025.03.14) |
| Dec 14, 2025 | 31.72% (0.31720) | 96.62th | v4 (v2025.03.14) |
| Dec 13, 2025 | 36.02% (0.36015) | 96.93th | v4 (v2025.03.14) |
| Aug 10, 2025 | 20.96% (0.20956) | 95.39th | v4 (v2025.03.14) |
| Jun 4, 2025 | 11.96% (0.11956) | 93.37th | v4 (v2025.03.14) |
| Mar 30, 2025 | 19.03% (0.19027) | 94.84th | v4 (v2025.03.14) |
| Mar 29, 2025 | 23.66% (0.23665) | 93.56th | v4 (v2025.03.14) |
| Mar 17, 2025 | 19.03% (0.19027) | 94.85th | v4 (v2025.03.14) |
| Dec 17, 2024 | 20.29% (0.20289) | 96.35th | v3 (v2023.03.01) |
| Dec 12, 2024 | 8.27% (0.08265) | 94.64th | v3 (v2023.03.01) |
| Jul 18, 2023 | 7.28% (0.07277) | 93.14th | v3 (v2023.03.01) |
| Jun 17, 2023 | 5.10% (0.05098) | 91.75th | v3 (v2023.03.01) |
| Mar 7, 2023 | 4.77% (0.04774) | 91.41th | v3 (v2023.03.01) |
| Mar 6, 2023 | 7.31% (0.07312) | 92.53th | v2 (v2022.01.01) |
| May 4, 2022 | 7.31% (0.07312) | 91.85th | v2 (v2022.01.01) |
| Apr 1, 2022 | 7.12% (0.07124) | 91.52th | v2 (v2022.01.01) |
| Feb 4, 2022 | 7.12% (0.07124) | 80.03th | v2 (v2022.01.01) |
Weaknesses (1)
References (33)
- http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00020.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00048.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00026.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00042.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-updates/2015-11/msg00093.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-updates/2016-05/msg00114.html vendor-advisoryx_refsource_SUSE
- http://packetstormsecurity.com/files/134082/FreeBSD-Security-Advisory-ntp-Authentication-Bypass.html x_refsource_MISC
- http://packetstormsecurity.com/files/134137/Slackware-Security-Advisory-ntp-Updates.html x_refsource_MISC
- http://support.ntp.org/bin/view/Main/NtpBug2920 x_refsource_CONFIRMPatchVendor Advisory
- http://support.ntp.org/bin/view/Main/SecurityNotice#October_2015_NTP_Security_Vulner
- http://talosintel.com/reports/TALOS-2015-0064/
- http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20151021-ntp vendor-advisoryx_refsource_CISCO
- http://www.securityfocus.com/archive/1/536737/100/0/threaded mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/archive/1/536760/100/0/threaded mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/archive/1/536796/100/0/threaded mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/archive/1/536833/100/0/threaded mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/archive/1/archive/1/536737/100/100/threaded mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/archive/1/archive/1/536760/100/100/threaded mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/archive/1/archive/1/536796/100/100/threaded mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/archive/1/archive/1/536833/100/100/threaded mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/bid/77273 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1033951 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- http://www.talosintel.com/vulnerability-reports/ x_refsource_MISC
- http://www.ubuntu.com/usn/USN-2783-1 vendor-advisoryx_refsource_UBUNTU
- https://access.redhat.com/security/cve/CVE-2015-7853 Vendor Advisory
- https://bto.bluecoat.com/security-advisory/sa103 x_refsource_CONFIRM
- https://bugzilla.redhat.com/show_bug.cgi?id=1274262 x_refsource_CONFIRMIssue TrackingThird Party AdvisoryVDB Entry
- https://cert-portal.siemens.com/productcert/pdf/ssa-211752.pdf x_refsource_CONFIRM
- https://nvd.nist.gov/vuln/detail/CVE-2015-7853
- 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://us-cert.cisa.gov/ics/advisories/icsa-21-159-11 x_refsource_MISC
- https://www.cve.org/CVERecord?id=CVE-2015-7853
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 16, 2015
Link CVE-2015-7853
CISA Vulnrichment
Updated n/a