CVE-2019-1977: Cisco Nexus 9000 Series Fabric Switches ACI Mode Border Leaf Endpoint Learning Vulnerability
First published: Wed Aug 28 2019(Updated: )
A vulnerability within the Endpoint Learning feature of Cisco Nexus 9000 Series Switches running in Application Centric Infrastructure (ACI) mode could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an endpoint device in certain circumstances. The vulnerability is due to improper endpoint learning when packets are received on a specific port from outside the ACI fabric and destined to an endpoint located on a border leaf when Disable Remote Endpoint Learning has been enabled. This can result in a Remote (XR) entry being created for the impacted endpoint that will become stale if the endpoint migrates to a different port or leaf switch. This results in traffic not reaching the impacted endpoint until the Remote entry can be relearned by another mechanism.
Credit: ykramarz@cisco.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Cisco Nx-os | =12.3\(1h\) | |
| Cisco Nx-os | =13.1\(2m\) | |
| Cisco Nx-os | =13.1\(2o\) | |
| Cisco Nx-os | =13.1\(2p\) | |
| Cisco Nexus 9000 | ||
| Cisco Nexus 93108tc-ex | ||
| Cisco Nexus 93108tc-fx | ||
| Cisco Nexus 93120tx | ||
| Cisco Nexus 93128tx | ||
| Cisco Nexus 93180lc-ex | ||
| Cisco Nexus 93180yc-ex | ||
| Cisco Nexus 93180yc-fx | ||
| Cisco Nexus 9332pq | ||
| Cisco Nexus 9336c-fx2 | ||
| Cisco Nexus 9336pq | ||
| Cisco Nexus 9348gc-fxp | ||
| Cisco Nexus 9364c | ||
| Cisco Nexus 9372px | ||
| Cisco Nexus 9372px-e | ||
| Cisco Nexus 9372tx | ||
| Cisco Nexus 9372tx-e | ||
| Cisco Nexus 9396px | ||
| Cisco Nexus 9396tx | ||
| Cisco Nexus 9504 | ||
| Cisco Nexus 9508 | ||
| Cisco Nexus 9516 |
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Reference Links
Frequently Asked Questions
What is the vulnerability ID for this Cisco Nexus 9000 Series Switches vulnerability?
The vulnerability ID is CVE-2019-1977.
What is the severity of CVE-2019-1977?
The severity of CVE-2019-1977 is high with a CVSS score of 7.5.
What is the affected software for CVE-2019-1977?
The affected software for CVE-2019-1977 is Cisco Nexus 9000 Series Switches running in Application Centric Infrastructure (ACI) mode.
What is the impact of CVE-2019-1977?
CVE-2019-1977 could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an endpoint device in certain circumstances.
How can I fix CVE-2019-1977?
There is currently no fix available for CVE-2019-1977, but Cisco has provided mitigations in their advisory.
- collector/nvd-index
- agent/type
- agent/softwarecombine
- collector/mitre-cve
- source/MITRE
- agent/severity
- agent/references
- agent/weakness
- agent/title
- agent/last-modified-date
- agent/author
- agent/first-publish-date
- agent/tags
- agent/description
- agent/event
- vendor/cisco
- canonical/cisco nx-os
- version/cisco nx-os/12.3\(1h\)
- version/cisco nx-os/13.1\(2m\)
- version/cisco nx-os/13.1\(2o\)
- version/cisco nx-os/13.1\(2p\)
- canonical/cisco nexus 9000
- canonical/cisco nexus 93108tc-ex
- canonical/cisco nexus 93108tc-fx
- canonical/cisco nexus 93120tx
- canonical/cisco nexus 93128tx
- canonical/cisco nexus 93180lc-ex
- canonical/cisco nexus 93180yc-ex
- canonical/cisco nexus 93180yc-fx
- canonical/cisco nexus 9332pq
- canonical/cisco nexus 9336c-fx2
- canonical/cisco nexus 9336pq
- canonical/cisco nexus 9348gc-fxp
- canonical/cisco nexus 9364c
- canonical/cisco nexus 9372px
- canonical/cisco nexus 9372px-e
- canonical/cisco nexus 9372tx
- canonical/cisco nexus 9372tx-e
- canonical/cisco nexus 9396px
- canonical/cisco nexus 9396tx
- canonical/cisco nexus 9504
- canonical/cisco nexus 9508
- canonical/cisco nexus 9516