7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
0.937 High
EPSS
Percentile
98.9%
An attacker who knows the origin timestamp and can send a spoofed packet
containing a CRYPTO-NAK to an ephemeral peer target before any other
response is sent can demobilize that association.
Credit to Miroslav Lichvar of Red Hat
An attacker who is able to spoof packets with correct origin timestamps from
enough servers before the expected response packets arrive at the target
machine can affect some peer variables and, for example, cause a false leap
indication to be set. Credit to Jakub Prokes of Red Hat
An attacker who is able to spoof a packet with a correct origin timestamp
before the expected response packet arrives at the target machine can send a
CRYPTO_NAK or a bad MAC and cause the association’s peer variables to be
cleared. If this can be done often enough, it will prevent that association
from working. Credit to Miroslav Lichvar of Red Hat
The fix for NtpBug2978 does not cover broadcast associations, so broadcast
clients can be triggered to flip into interleave mode.
Credit to Miroslav Lichvar of Red Hat
The fix for Sec 3007 in ntp-4.2.8p7 contained a bug that could cause ntpd to
crash. Credit to Nicolas Edet of Cisco
support.ntp.org/bin/view/Main/NtpBug3042
support.ntp.org/bin/view/Main/NtpBug3043
support.ntp.org/bin/view/Main/NtpBug3044
support.ntp.org/bin/view/Main/NtpBug3045
support.ntp.org/bin/view/Main/NtpBug3046
access.redhat.com/security/cve/cve-2016-4953
access.redhat.com/security/cve/cve-2016-4954
access.redhat.com/security/cve/cve-2016-4955
access.redhat.com/security/cve/cve-2016-4956
access.redhat.com/security/cve/cve-2016-4957
7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
0.937 High
EPSS
Percentile
98.9%