CVE-2019-1594: A vulnerability in the 802.1X implementation for Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (...

Description

A vulnerability in the 802.1X implementation for Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to incomplete input validation of Extensible Authentication Protocol over LAN (EAPOL) frames. An attacker could exploit this vulnerability by sending a crafted EAPOL frame to an interface on the targeted device. A successful exploit could allow the attacker to cause the Layer 2 (L2) forwarding process to restart multiple times, leading to a system-level restart of the device and a DoS condition. Note: This vulnerability affects only NX-OS devices configured with 802.1X functionality. Cisco Nexus 1000V Switch for VMware vSphere devices are affected in versions prior to 5.2(1)SV3(1.4b). Nexus 3000 Series Switches are affected in versions prior to 7.0(3)I7(4). Nexus 3500 Platform Switches are affected in versions prior to 7.0(3)I7(4). Nexus 2000, 5500, 5600, and 6000 Series Switches are affected in versions prior to 7.3(5)N1(1) and 7.1(5)N1(1b). Nexus 7000 and 7700 Series Switches are affected in versions prior to 8.2(3). Nexus 9000 Series Fabric Switches in ACI Mode are affected in versions prior to 13.2(1l). Nexus 9000 Series Switches in Standalone NX-OS Mode are affected in versions prior to 7.0(3)I7(4).

Metrics

EPSS Probability

0.80%

51.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Nx-Os	< 5.2\(1\)sv3\(1.4b\)
Cisco	Nx-Os	>= 7.0\(3\)i7, < 7.0\(3\)i7\(4\)
Cisco	Nx-Os	< 7.1\(5\)n1\(1b\)
Cisco	Nx-Os	>= 8.3, < 8.3\(1\)
Cisco	Nx-Os	< 13.2\(1l\)
Cisco	Nx-Os	>= 7.2, < 7.3\(5\)n1\(1\)
Cisco	Nx-Os	>= 8.0, < 8.2\(3\)
Cisco	Nx-Os	>= 7.2, < 7.3\(3\)d1\(1\)
Cisco	Nx-Os	>= 6.2, < 6.2\(20a\)

References

http://www.securityfocus.com/bid/107325Third Party Advisory, VDB Entry
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190306-nx-os-lan-authPatch, Vendor Advisory
http://www.securityfocus.com/bid/107325Third Party Advisory, VDB Entry
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190306-nx-os-lan-authPatch, Vendor Advisory

Timeline

Published: Mar 6, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-1594?

A vulnerability in the 802.1X implementation for Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to incomplete input validation of Extensible Authentication Protocol over LAN (EAPOL) frames. An attacker could exploit this vulnerability by sending a crafted EAPOL frame to an interface on the targeted device. A successful exploit could allow the attacker to cause the Layer 2 (L2) forwarding process to restart multiple times, leading to a system-level restart of the device and a DoS condition. Note: This vulnerability affects only NX-OS devices configured with 802.1X functionality. Cisco Nexus 1000V Switch for VMware vSphere devices are affected in versions prior to 5.2(1)SV3(1.4b). Nexus 3000 Series Switches are affected in versions prior to 7.0(3)I7(4). Nexus 3500 Platform Switches are affected in versions prior to 7.0(3)I7(4). Nexus 2000, 5500, 5600, and 6000 Series Switches are affected in versions prior to 7.3(5)N1(1) and 7.1(5)N1(1b). Nexus 7000 and 7700 Series Switches are affected in versions prior to 8.2(3). Nexus 9000 Series Fabric Switches in ACI Mode are affected in versions prior to 13.2(1l). Nexus 9000 Series Switches in Standalone NX-OS Mode are affected in versions prior to 7.0(3)I7(4).

How severe is CVE-2019-1594?

Severity scoring for CVE-2019-1594 is pending analysis. The EPSS model estimates a 0.80% probability of exploitation in the next 30 days.

How do I fix CVE-2019-1594?

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.