QwikSec

Security Database

CVE

CWE

Training

CVE Database
/

CVE-2021-28511

Back to search

CVE-2021-28511

Published: Aug 5, 2022

Modified: Jun 2, 2026

PUBLISHED

CVSS v3.1

5.8

MEDIUM

Description

This advisory documents the impact of an internally found vulnerability in Arista EOS for security ACL bypass. The impact of this vulnerability is that the security ACL drop rule might be bypassed if a NAT ACL rule filter with permit action matches the packet flow. This could allow a host with an IP address in a range that matches the range allowed by a NAT ACL and a range denied by a Security ACL to be forwarded incorrectly as it should have been denied by the Security ACL. This can enable an ACL bypass.

VendorProductVersions

Arista Networks

EOS

affected
4.24.0 - <= 4.24.9
affected
4.25.0 - <= 4.25.8
affected
4.26.0 - <= 4.26.5
affected
4.27.0 - <= 4.27.3

Weaknesses (CWE)

CWE-284

CVSS v3.1 Details

CVSS v3.1 Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

None

Integrity

Low

Availability

None

References

Security Training

Train your team to recognize and prevent security threats with our comprehensive security awareness program.

Start Training

Vulnerability Scanning

Discover vulnerabilities in your applications and infrastructure before attackers do.

Scan Now