Cisco Nexus 9000 Series Fabric Switches Application Centric Infrastructure Mode Default SSH Key Vulnerability

published 2019-05-03 7y ago modified 2026-06-17 4mo ago also EUVD-2019-10361

cvss: 9.8; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 3.5%; EPSS 3.5% chance of exploitation in 30 days, percentile 89%
public exploits: 0; none known

A vulnerability in the SSH key management for the Cisco Nexus 9000 Series Application Centric Infrastructure (ACI) Mode Switch Software could allow an unauthenticated, remote attacker to connect to the affected system with the privileges of the root user. The vulnerability is due to the presence of a default SSH key pair that is present in all devices. An attacker could exploit this vulnerability by opening an SSH connection via IPv6 to a targeted device using the extracted key materials. An exploit could allow the attacker to access the system with the privileges of the root user. This vulnerability is only exploitable over IPv6; IPv4 is not vulnerable.

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CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: total
Assessed: last yr. (2024-11-19)

Exploit prediction

3.45% chance of exploitation in the next 30 days, higher than 89% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
CNA	3.0	9.8	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	10.0	AV:N/AC:L/Au:N/C:C/I:C/A:C

Affected products

Cisco Cisco NX-OS Software for Nexus 9000 Series Fabric Switches ACI Mode 11.0.1b

Classification

Weakness

CWE-310 Cryptographic Issues
CWE-1188 Initialization of a Resource with an Insecure Default

References

tools.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-20190501-nexus9k-sshkey
vendor-advisory

Sources

CVE List CVE-2019-1804
NVD CVE-2019-1804

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