CVE-2011-2581

What it is

The ACL implementation in Cisco NX-OS 5.0(2) and 5.0(3) before 5.0(3)N2(1) on Nexus 5000 series switches, and NX-OS before 5.0(3)U1(2a) on Nexus 3000 series switches, does not properly handle comments in conjunction with deny statements, which allows remote attackers to bypass intended access restrictions in opportunistic circumstances by sending packets, aka Bug IDs CSCto09813 and CSCtr61490.

At a glance

Exploitability

Can be exploited over the network without logging in. Limited direct impact.

Exploit odds

2.0% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2011-09-14 16:05 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-16 23:31 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 2.0% in the next 30 days (EPSS).
• Severity: 5.0 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2011-09-14 16:05 UTC

Last modified

2026-06-16 23:31 UTC

Exploit probability

2.0% · EPSS, next 30 days

Weakness

CWE-264

Record status

Modified

Affected

• Cisco nx-os 5.0\(2\)
• Cisco nx-os 5.0\(3\)n1\(1\)
• Cisco nx-os 5.0\(3\)n1\(1a\)
• Cisco nx-os 5.0\(3\)n1\(1b\)
• Cisco nx-os 5.0\(3\)
• Cisco nx-os 5.0\(3\)n1\(1c\)
• Cisco Nexus 5000
• Cisco nx-os ≤ 5.0\(3\)u1\(2\)

Attack profile CVSS 2.0 · 5.0

Attack vector

Network

Complexity

Low

Authentication

None

Confidentiality

Partial

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2011-2581.md and follow it. Check whether this project is affected by CVE-2011-2581. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

Copy as ticket · More options · Status badge