What is CVE-2021-1591?

CVE-2021-1591 is a medium-severity vulnerability in Cisco Nx-Os Software, classified under Improper Access Control. CVSS score: 5.8/10. Published 2021-08-25.

How severe is CVE-2021-1591?

Medium severity. CVSS v3 base score is 5.8 out of 10.

Is CVE-2021-1591 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Cisco Nx-Os Software

CVE-2021-1591

A vulnerability in the EtherChannel port subscription logic of Cisco Nexus 9500 Series Switches could allow an unauthenticated, remote attacker to bypass access control list (ACL) rules that are configured on an affected device. This vulnerability is due to oversubscription of resources that occurs when applying ACLs to port channel interfaces. An attacker could exploit this vulnerability by attempting to access network resources that are protected by the ACL. A successful exploit could allow the attacker to access network resources that would be protected by the ACL that was applied on the port channel interface.

EPSS: 0.010 (59.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N.

Affected products

Weakness classification (CWE)

CWE-284 — Improper Access Control

Public proof-of-concept exploits

n0-traces/cve_

References

psirt@cisco.com (x_refsource_CISCO, vendor-advisory, Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-1591?: CVE-2021-1591 is a medium-severity vulnerability in Cisco Nx-Os Software, classified under Improper Access Control. CVSS score: 5.8/10. Published 2021-08-25.
How severe is CVE-2021-1591?: Medium severity. CVSS v3 base score is 5.8 out of 10.
Is CVE-2021-1591 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.