cisco-sa-20190828-nxos-ntp-dos: Cisco NX-OS Software Network Time Protocol Denial of Service Vulnerability
First published: Wed Aug 28 2019(Updated: )
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. Cisco has released software updates that address this vulnerability. There are workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190828-nxos-ntp-dos
Credit: This vulnerability was found during the resolution a Cisco TAC support case
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Cisco NX-OS Software | =6.2<6.2(29) | 6.2(29) |
| Cisco NX-OS Software | ||
| Cisco NX-OS Software | =6.0(2)A8<6.0(2)A8(11) | 6.0(2)A8(11) |
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Reference Links
Frequently Asked Questions
What is the Cisco NX-OS Software Network Time Protocol Denial of Service vulnerability?
It is a vulnerability in the Network Time Protocol (NTP) feature of Cisco NX-OS Software that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
How does the vulnerability in Cisco NX-OS Software Network Time Protocol Denial of Service occur?
The vulnerability occurs due to excessive use of system resources when the affected device is logging a certain type of NTP packet at a high rate.
What is the severity of Cisco NX-OS Software Network Time Protocol Denial of Service vulnerability?
The severity of this vulnerability is high with a CVSS score of 8.6.
Which versions of Cisco NX-OS Software are affected by the Network Time Protocol Denial of Service vulnerability?
Cisco NX-OS Software versions 6.2 up to 6.2(29) and 6.0(2)A8 up to 6.0(2)A8(11) are affected by this vulnerability.
Is there a remedy available for the Cisco NX-OS Software Network Time Protocol Denial of Service vulnerability?
Yes, Cisco has provided a remedy for some versions of Cisco NX-OS Software. Please refer to the Cisco Security Advisory for more information.
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