CVE-2019-1968: A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an NX-API system process to une...

Description

A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an NX-API system process to unexpectedly restart. The vulnerability is due to incorrect validation of the HTTP header of a request that is sent to the NX-API. An attacker could exploit this vulnerability by sending a crafted HTTP request to the NX-API on an affected device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition in the NX-API service; however, the NX-OS device itself would still be available and passing network traffic. Note: The NX-API feature is disabled by default.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

1.77%

75.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Nx-Os	7.3
Cisco	Nx-Os	8.1
Cisco	Nx-Os	8.2
Cisco	Nx-Os	8.3
Cisco	Nx-Os	6.1\(2\)i2
Cisco	Nx-Os	6.1\(2\)i3
Cisco	Nx-Os	7.0\(3\)i4
Cisco	Nx-Os	7.0\(3\)i7
Cisco	Nx-Os	9.2
Cisco	Nx-Os	6.0\(2\)a8
Cisco	Nx-Os	7.0\(3\)f
Cisco	Nx-Os	7.1
Cisco	Nx-Os	7.2
Cisco	Nx-Os	8.0

References

Timeline

Published: Aug 30, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-1968?

A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an NX-API system process to unexpectedly restart. The vulnerability is due to incorrect validation of the HTTP header of a request that is sent to the NX-API. An attacker could exploit this vulnerability by sending a crafted HTTP request to the NX-API on an affected device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition in the NX-API service; however, the NX-OS device itself would still be available and passing network traffic. Note: The NX-API feature is disabled by default.

How severe is CVE-2019-1968?

CVE-2019-1968 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.77% probability of exploitation in the next 30 days.

How do I fix CVE-2019-1968?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.