This vulnerability involves incorrect initialization of resources (CWE-1419) in Arista EOS when running on affected platforms with dual switch cards and ingress Security ACLs configured on shared-mode SVIs. Specifically, restarting the secondary switchcard forwarding agent or inserting the secondary switchcard can cause the security ACLs on shared SVIs to cease functioning properly, resulting in incorrect packet filtering behavior. The vulnerability was internally discovered by Arista and has not been reported exploited in the wild.

The impact is limited to the potential failure of security ACLs on shared SVIs to enforce intended packet filtering rules after certain operations on the secondary switchcard. This may allow packets that should be denied or block packets that should be permitted, leading to reduced security enforcement on affected network segments. There is no reported confidentiality or availability impact beyond this ACL malfunction.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since no patch links or official fixes are provided, users should monitor Arista's advisories for updates. Until a fix is available, avoid restarting or inserting the secondary switchcard on affected platforms with ingress Security ACLs configured on shared SVIs in shared mode to prevent ACL malfunction.