Vulnerability · Published Aug 25, 2021 · Assigned by cisco

CVE-2021-1591Cisco Nexus 9500 Series Switches Access Control List Bypass Vulnerability

Medium 5.8

In plain English

A medium-severity improper access control in Cisco NX-OS Software from Cisco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 63% of all known vulnerabilities).

Severity (CVSS 3.1)5.8Medium

Exploit odds (30 days)1.0%top 37.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
Cisco	Cisco NX-OS Software	n/a

Weakness: CWE-284 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

References

20210825 Cisco Nexus 9500 Series Switches Access Control List Bypass Vulnerability vendor-advisory, x_refsource_CISCO