PT-2021-5325 · Cisco · Cisco Nexus 9500 Series Switches+1

Published 2021-08-25 · Updated 2022-07-08 · CVE-2021-1591

Positive Technologies (AI Summary)

CVSS v3.1

5.8

Medium

Base vector

AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Name of the Vulnerable Software and Affected Versions Cisco Nexus 9500 Series Switches (affected versions not specified)

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

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Improper Authentication

Improper Access Control

Weakness Enumeration

CWE-287

CWE-284

Related Identifiers

BDU:2021-06153

CVE-2021-1591

Affected Products

Cisco Nexus

Cisco Nexus 9500 Series Switches

References · 8

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nexus-acl-vrvQYPVe · Vendor Advisory
• https://bdu.fstec.ru/vul/2021-06153 · Security Note
• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nexus-acl-vrvQYPVe · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-1591 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-1591 · Security Note
• https://t.me/cvenotify/20100 · Telegram Post
• https://t.me/cybersecuritytechnologies/4232 · Telegram Post
• https://t.me/cvenotify/20630 · Telegram Post