CVE-2015-7704: Citrix Xenserver

High severity, CVSS 7.5. EPSS: 11% chance of exploitation in the next 30 days.

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: version 6.0.2 only; version 6.2.0 only; version 6.5 only; version 7.0 only
• Debian Debian Linux: version 7.0 only; version 8.0 only; version 9.0 only
• McAfee Enterprise Security Manager: before 10.4.0 (fixed in 10.4.0); from 11.0.0, before 11.2.0 (fixed in 11.2.0)
• Netapp Clustered Data Ontap: affected versions not specified
• Netapp Data Ontap: affected versions not specified
• Netapp Oncommand Performance Manager: affected versions not specified
• Netapp Oncommand Unified Manager: affected versions not specified
• Ntp Ntp: from 4.2.0, before 4.2.8 (fixed in 4.2.8); from 4.3.0, before 4.3.77 (fixed in 4.3.77); version 4.2.8 only
• Red Hat Enterprise Linux Desktop: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server Aus: version 6.5 only; version 6.6 only; version 7.3 only; version 7.4 only; version 7.6 only; version 7.7 only
• Red Hat Enterprise Linux Server Eus: version 6.5 only; version 6.6 only; version 6.7 only; version 7.1 only; version 7.3 only; version 7.4 only; …
• Red Hat Enterprise Linux Server Tus: version 6.5 only; version 6.6 only; version 7.3 only; version 7.6 only; version 7.7 only
• Red Hat Enterprise Linux Workstation: version 6.0 only; version 7.0 only

Published 2017-08-07. Last modified 2026-06-17.