CVE-2019-1967
HIGHCisco NX-OS - Unauthenticated Denial of Service via MODE_PRIVATE NTP Packet Flood
Title source: llmDescription
A vulnerability in the Network Time Protocol (NTP) feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to excessive use of system resources when the affected device is logging a drop action for received MODE_PRIVATE (Mode 7) NTP packets. An attacker could exploit this vulnerability by flooding the device with a steady stream of Mode 7 NTP packets. A successful exploit could allow the attacker to cause high CPU and memory usage on the affected device, which could cause internal system processes to restart or cause the affected device to unexpectedly reload. Note: The NTP feature is enabled by default.
References (1)
Core 1
Core References
Vendor Advisory vendor-advisory
x_refsource_cisco
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190828-nxos-ntp-dos
Scores
CVSS v3
7.5
EPSS
0.0197
EPSS Percentile
77.9%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-399
CWE-400
Status
published
Products (20)
cisco/nx-os
6.2
cisco/nx-os
7.3
cisco/nx-os
8.1
cisco/nx-os
8.2
cisco/nx-os
8.3
cisco/nx-os
6.0\(2\)a8\(9.7\)
cisco/nx-os
6.0\(2\)u6
cisco/nx-os
7.0\(3\)i
cisco/nx-os
9.2
cisco/nx-os
9.2\(1\)
... and 10 more
Published
Aug 30, 2019
Tracked Since
Feb 18, 2026