PT-2016-6188 · Cisco+4 · Ntp+6

Miroslav Lichvar

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Published

2016-06-03

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Updated

2024-06-15

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CVE-2016-4955

CVSS v3.1

5.9

Medium

VectorAV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions NTP versions 4.x before 4.2.8p8
Description The issue allows remote attackers to cause a denial of service by sending a spoofed crypto-NAK packet or a packet with an incorrect MAC value at a certain time when autokey is enabled. This can lead to peer-variable clearing and association outage. Multiple Cisco products that incorporate a version of the Network Time Protocol daemon package are affected, potentially allowing an unauthenticated, remote attacker to cause a denial of service condition or modify the time being advertised by a device acting as a Network Time Protocol server.
Recommendations For NTP versions 4.x before 4.2.8p8, update to version 4.2.8p8 or later to resolve the issue. As a temporary workaround, consider disabling the autokey feature until a patch is available. Restrict access to the NTP server to minimize the risk of exploitation. Avoid using the autokey feature in the affected NTP version until the issue is resolved.

Fix

DoS

Race Condition

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Weakness Enumeration

Related Identifiers

ALT-PU-2017-2335
CVE-2016-4955
MGASA-2016-0219
OPENSUSE-SU-2016_1583-1
OPENSUSE-SU-2016_1636-1
OPENSUSE-SU-2024:10181-1
SUSE-SU-2016:1563-1
SUSE-SU-2016:1568-1
SUSE-SU-2016:1584-1
SUSE-SU-2016:1602-1
USN-3096-1

Affected Products

Alt Linux
Cisco Ios Xr
Cisco Nexus
Freebsd
Ntp
Suse
Ubuntu