Vulnerability Details : CVE-2019-1977
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.
Vulnerability category: Denial of service
Products affected by CVE-2019-1977
- cpe:2.3:o:cisco:nx-os:12.3\(1h\):*:*:*:*:*:*:*
- cpe:2.3:o:cisco:nx-os:13.1\(2m\):*:*:*:*:*:*:*
- cpe:2.3:o:cisco:nx-os:13.1\(2o\):*:*:*:*:*:*:*
- cpe:2.3:o:cisco:nx-os:13.1\(2p\):*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2019-1977
0.16%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 52 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2019-1977
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
4.3
|
MEDIUM | AV:N/AC:M/Au:N/C:N/I:N/A:P |
8.6
|
2.9
|
NIST | |
7.5
|
HIGH | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
3.9
|
3.6
|
NIST | |
6.8
|
MEDIUM | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H |
2.2
|
4.0
|
Cisco Systems, Inc. |
CWE ids for CVE-2019-1977
-
Assigned by:
- nvd@nist.gov (Primary)
- ykramarz@cisco.com (Secondary)
References for CVE-2019-1977
-
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190828-nexus-aci-dos
Cisco Nexus 9000 Series Fabric Switches ACI Mode Border Leaf Endpoint Learning VulnerabilityVendor Advisory
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