Synopsis
Moderate: ntp security update
Type/Severity
Security Advisory: Moderate
Topic
An update for ntp is now available for Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7.
Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.
Description
The Network Time Protocol (NTP) is used to synchronize a computer's time with another referenced time source. These packages include the ntpd service which continuously adjusts system time and utilities used to query and configure the ntpd service.
Security Fix(es):
- It was found that when ntp is configured with rate limiting for all associations the limits are also applied to responses received from its configured sources. A remote attacker who knows the sources can cause a denial of service by preventing ntpd from accepting valid responses from its sources. (CVE-2016-7426)
- A flaw was found in the control mode functionality of ntpd. A remote attacker could send a crafted control mode packet which could lead to information disclosure or result in DDoS amplification attacks. (CVE-2016-9310)
- A flaw was found in the way ntpd implemented the trap service. A remote attacker could send a specially crafted packet to cause a null pointer dereference that will crash ntpd, resulting in a denial of service. (CVE-2016-9311)
- A flaw was found in the way ntpd running on a host with multiple network interfaces handled certain server responses. A remote attacker could use this flaw which would cause ntpd to not synchronize with the source. (CVE-2016-7429)
- A flaw was found in the way ntpd calculated the root delay. A remote attacker could send a specially-crafted spoofed packet to cause denial of service or in some special cases even crash. (CVE-2016-7433)
Solution
For details on how to apply this update, which includes the changes described in this advisory, refer to:
https://access.redhat.com/articles/11258
After installing this update, the ntpd daemon will restart automatically.
Affected Products
-
Red Hat Enterprise Linux Server 7 x86_64
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Red Hat Enterprise Linux Server 6 x86_64
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Red Hat Enterprise Linux Server 6 i386
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Red Hat Enterprise Linux Server - Extended Update Support 7.6 x86_64
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Red Hat Enterprise Linux Server - Extended Update Support 7.5 x86_64
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Red Hat Enterprise Linux Server - Extended Update Support 7.4 x86_64
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Red Hat Enterprise Linux Server - Extended Update Support 7.3 x86_64
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Red Hat Enterprise Linux Server - AUS 7.6 x86_64
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Red Hat Enterprise Linux Server - AUS 7.4 x86_64
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Red Hat Enterprise Linux Workstation 7 x86_64
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Red Hat Enterprise Linux Workstation 6 x86_64
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Red Hat Enterprise Linux Workstation 6 i386
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Red Hat Enterprise Linux Desktop 7 x86_64
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Red Hat Enterprise Linux Desktop 6 x86_64
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Red Hat Enterprise Linux Desktop 6 i386
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Red Hat Enterprise Linux for IBM z Systems 7 s390x
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Red Hat Enterprise Linux for IBM z Systems 6 s390x
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Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
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Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
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Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.4 s390x
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Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.3 s390x
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Red Hat Enterprise Linux for Power, big endian 7 ppc64
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Red Hat Enterprise Linux for Power, big endian 6 ppc64
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Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
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Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
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Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
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Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.3 ppc64
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Red Hat Enterprise Linux for Scientific Computing 7 x86_64
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Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
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Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
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Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
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Red Hat Enterprise Linux EUS Compute Node 7.3 x86_64
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Red Hat Enterprise Linux Server - AUS 7.3 x86_64
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Red Hat Enterprise Linux for Power, little endian 7 ppc64le
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Red Hat Enterprise Linux for Scientific Computing 6 x86_64
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Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.6 ppc64le
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Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.5 ppc64le
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Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.4 ppc64le
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Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.3 ppc64le
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Red Hat Enterprise Linux Server - TUS 7.6 x86_64
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Red Hat Enterprise Linux Server - TUS 7.3 x86_64
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Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.6 ppc64le
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Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.4 ppc64le
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Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.3 ppc64le
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Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.6 x86_64
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Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.4 x86_64
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Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.3 x86_64
Fixes
- BZ - 1397319 - CVE-2016-9310 ntp: Mode 6 unauthenticated trap information disclosure and DDoS vector
- BZ - 1397341 - CVE-2016-7429 ntp: Attack on interface selection
- BZ - 1397345 - CVE-2016-7426 ntp: Client rate limiting and server responses
- BZ - 1397347 - CVE-2016-7433 ntp: Broken initial sync calculations regression
- BZ - 1398350 - CVE-2016-9311 ntp: Null pointer dereference when trap service is enabled
CVEs
References
Vulmon