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Vulnerability record · CVE-2015-7691 · published 7 August 2017

CVE-2015-7691: Ntp improper input validation vulnerability

Ntp · Ntp

The crypto_xmit 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 (crash) via crafted packets containing particular autokey operations. NOTE: This vulnerability exists due to an incomplete fix for CVE-2014-9750.

7.5 CVSS 3.1 High EPSS 7.1% · top 6.0% CWE-20 · Improper input validation
7.5CVSS 3.1 base score, v2 5.0
7.1%EPSS exploitation probability, 30 days
NoNot in CISA KEV
13Affected product versions listed by NVD
20References
17 Jun 2026Last modified by NVD

Description

The crypto_xmit 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 (crash) via crafted packets containing particular autokey operations. NOTE: This vulnerability exists due to an incomplete fix for CVE-2014-9750.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

13 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://rhn.redhat.com/errata/RHSA-2016-0780.html Third Party Advisory
http://rhn.redhat.com/errata/RHSA-2016-2583.html Third Party Advisory
http://support.ntp.org/bin/view/Main/NtpBug2899 Vendor Advisory
http://www.debian.org/security/2015/dsa-3388 Third Party Advisory
http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html Third Party Advisory
http://www.securityfocus.com/bid/77274 Third Party AdvisoryVDB Entry
http://www.securitytracker.com/id/1033951 Third Party AdvisoryVDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=1274254 Issue TrackingThird Party AdvisoryVDB Entry
https://security.gentoo.org/glsa/201607-15 Third Party AdvisoryVDB Entry
https://security.netapp.com/advisory/ntap-20171004-0001/ Third Party Advisory
http://rhn.redhat.com/errata/RHSA-2016-0780.html Third Party Advisory
http://rhn.redhat.com/errata/RHSA-2016-2583.html Third Party Advisory
http://support.ntp.org/bin/view/Main/NtpBug2899 Vendor Advisory
http://www.debian.org/security/2015/dsa-3388 Third Party Advisory
http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html Third Party Advisory
http://www.securityfocus.com/bid/77274 Third Party AdvisoryVDB Entry
http://www.securitytracker.com/id/1033951 Third Party AdvisoryVDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=1274254 Issue TrackingThird Party AdvisoryVDB Entry
https://security.gentoo.org/glsa/201607-15 Third Party AdvisoryVDB Entry
https://security.netapp.com/advisory/ntap-20171004-0001/ Third Party Advisory

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Source: NIST National Vulnerability Database (record CVE-2015-7691), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.