What’s Vulnerable › Vulnerabilities

CVE-2015-7704

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 10.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2017-08-07 · updated 2026-06-17
• Weakness: CWE-20

Description

The ntpd client in NTP 4.x before 4.2.8p4 and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service via a number of crafted "KOD" messages.

Affected products

• Citrix XenServer: 6.2.0, 6.5; 6.0.2, 7.0 (and their updates)
• Debian Linux: 7.0, 8.0, 9.0 (and their updates)
• McAfee, LLC McAfee Enterprise Security Manager (ESM): before 10.4.0; from 11.0.0 before 11.2.0 — fixed in 10.4.0, 11.2.0
• Clustered Data ONTAP: all versions
• NetApp Data ONTAP operating in 7-Mode: all versions
• NetApp Oncommand Performance Manager: all versions
• NetApp OnCommand Unified Manager for 7-Mode (core package): all versions
• NTP: from 4.2.0 before 4.2.8; from 4.3.0 before 4.3.77; 4.2.8-p1, 4.2.8-p1-beta1, 4.2.8-p1-beta2, 4.2.8-p1-beta3, 4.2.8-p1-beta4, 4.2.8-p1-beta5 (+10); 4.2.8 — fixed in 4.2.8, 4.3.77
• RedHat Enterprise Linux Desktop: 6.0, 7.0 (and their updates)
• RedHat Enterprise Linux Server: 6.0, 7.0 (and their updates)
• RedHat Enterprise Linux Server Aus: 6.5, 6.6, 7.3, 7.4, 7.6, 7.7 (and their updates)
• RedHat Enterprise Linux Server Eus: 6.5, 6.6, 6.7, 7.1, 7.3, 7.4 (+3) (and their updates)
• RedHat Enterprise Linux Server Tus: 6.5, 6.6, 7.3, 7.6, 7.7 (and their updates)
• RedHat Enterprise Linux Workstation: 6.0, 7.0 (and their updates)

How to fix

Upgrade to a fixed version: McAfee, LLC McAfee Enterprise Security Manager (ESM) 10.4.0, 11.2.0; NTP 4.2.8, 4.3.77. Check the vendor advisory for mitigations.

References

• http://bugs.ntp.org/show_bug.cgi?id=2901
• http://rhn.redhat.com/errata/RHSA-2015-1930.html
• http://rhn.redhat.com/errata/RHSA-2015-2520.html
• http://support.ntp.org/bin/view/Main/NtpBug2901
• http://support.ntp.org/bin/view/Main/SecurityNotice#October_2015_NTP_4_2_8p4_Securit
• http://www.debian.org/security/2015/dsa-3388
• http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
• http://www.securityfocus.com/bid/77280
• http://www.securitytracker.com/id/1033951
• https://bugzilla.redhat.com/show_bug.cgi?id=1271070
• https://eprint.iacr.org/2015/1020.pdf
• https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05270839

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