Security features bypass in Arista Extensible Operating System (EOS) - CVE-2021-28511

 

Security features bypass in Arista Extensible Operating System (EOS) - CVE-2021-28511

Published: May 17, 2025


Vulnerability identifier: #VU109357
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-28511
CWE-ID: CWE-254
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to bypass implemented ACL rules.

The vulnerability exists due to an error when handling traffic if a NAT ACL rule filter with permit action matches the packet flow. A remote attacker can bypass ACL rules.


Affected software

Arista Extensible Operating System (EOS)

How to mitigate CVE-2021-28511

Install updates from vendor's website.

Arista Extensible Operating System (EOS) - addressed in versions 4.24.10, 4.25.9, 4.26.6, 4.27.4, 4.28.0

External References

Related Security Bulletins